lnrpc: update docs for invoice amt_paid

This corrects the documentation for the `amt_paid` and `amt_paid_msat`
fields on the `Invoice` message to indicate that the fields will be set
if the state of the invoice is either accepted or settled, not only
settled. This reflects the actual behavior of lnd, as demonstrated in
the below `lncli` output:

```
"amt_paid": "10000",
"amt_paid_sat": "10",
"amt_paid_msat": "10000",
"state": "ACCEPTED",
```

lnrpc/invoicesrpc/invoices.swagger.json

@@ -533,12 +533,12 @@
         "amt_paid_sat": {
           "type": "string",
           "format": "int64",
-          "description": "The amount that was accepted for this invoice, in satoshis. This will ONLY\nbe set if this invoice has been settled. We provide this field as if the\ninvoice was created with a zero value, then we need to record what amount\nwas ultimately accepted. Additionally, it's possible that the sender paid\nMORE that was specified in the original invoice. So we'll record that here\nas well.\nNote: Output only, don't specify for creating an invoice."
+          "description": "The amount that was accepted for this invoice, in satoshis. This will ONLY\nbe set if this invoice has been settled or accepted. We provide this field\nas if the invoice was created with a zero value, then we need to record what\namount was ultimately accepted. Additionally, it's possible that the sender\npaid MORE that was specified in the original invoice. So we'll record that\nhere as well.\nNote: Output only, don't specify for creating an invoice."
         },
         "amt_paid_msat": {
           "type": "string",
           "format": "int64",
-          "description": "The amount that was accepted for this invoice, in millisatoshis. This will\nONLY be set if this invoice has been settled. We provide this field as if\nthe invoice was created with a zero value, then we need to record what\namount was ultimately accepted. Additionally, it's possible that the sender\npaid MORE that was specified in the original invoice. So we'll record that\nhere as well.\nNote: Output only, don't specify for creating an invoice."
+          "description": "The amount that was accepted for this invoice, in millisatoshis. This will\nONLY be set if this invoice has been settled or accepted. We provide this\nfield as if the invoice was created with a zero value, then we need to\nrecord what amount was ultimately accepted. Additionally, it's possible that\nthe sender paid MORE that was specified in the original invoice. So we'll\nrecord that here as well.\nNote: Output only, don't specify for creating an invoice."
         },
         "state": {
           "$ref": "#/definitions/InvoiceInvoiceState",

lnrpc/lightning.pb.go

@@ -11696,20 +11696,20 @@ type Invoice struct {
 	// Deprecated: Do not use.
 	AmtPaid int64 `protobuf:"varint,18,opt,name=amt_paid,json=amtPaid,proto3" json:"amt_paid,omitempty"`
 	// The amount that was accepted for this invoice, in satoshis. This will ONLY
-	// be set if this invoice has been settled. We provide this field as if the
+	// be set if this invoice has been settled or accepted. We provide this field
-	// invoice was created with a zero value, then we need to record what amount
+	// as if the invoice was created with a zero value, then we need to record what
-	// was ultimately accepted. Additionally, it's possible that the sender paid
-	// MORE that was specified in the original invoice. So we'll record that here
-	// as well.
-	// Note: Output only, don't specify for creating an invoice.
-	AmtPaidSat int64 `protobuf:"varint,19,opt,name=amt_paid_sat,json=amtPaidSat,proto3" json:"amt_paid_sat,omitempty"`
-	// The amount that was accepted for this invoice, in millisatoshis. This will
-	// ONLY be set if this invoice has been settled. We provide this field as if
-	// the invoice was created with a zero value, then we need to record what
 	// amount was ultimately accepted. Additionally, it's possible that the sender
 	// paid MORE that was specified in the original invoice. So we'll record that
 	// here as well.
 	// Note: Output only, don't specify for creating an invoice.
+	AmtPaidSat int64 `protobuf:"varint,19,opt,name=amt_paid_sat,json=amtPaidSat,proto3" json:"amt_paid_sat,omitempty"`
+	// The amount that was accepted for this invoice, in millisatoshis. This will
+	// ONLY be set if this invoice has been settled or accepted. We provide this
+	// field as if the invoice was created with a zero value, then we need to
+	// record what amount was ultimately accepted. Additionally, it's possible that
+	// the sender paid MORE that was specified in the original invoice. So we'll
+	// record that here as well.
+	// Note: Output only, don't specify for creating an invoice.
 	AmtPaidMsat int64 `protobuf:"varint,20,opt,name=amt_paid_msat,json=amtPaidMsat,proto3" json:"amt_paid_msat,omitempty"`
 	// The state the invoice is in.
 	// Note: Output only, don't specify for creating an invoice.

lnrpc/lightning.proto

@@ -3456,22 +3456,22 @@ message Invoice {
 
     /*
     The amount that was accepted for this invoice, in satoshis. This will ONLY
-    be set if this invoice has been settled. We provide this field as if the
+    be set if this invoice has been settled or accepted. We provide this field
-    invoice was created with a zero value, then we need to record what amount
+    as if the invoice was created with a zero value, then we need to record what
-    was ultimately accepted. Additionally, it's possible that the sender paid
+    amount was ultimately accepted. Additionally, it's possible that the sender
-    MORE that was specified in the original invoice. So we'll record that here
+    paid MORE that was specified in the original invoice. So we'll record that
-    as well.
+    here as well.
     Note: Output only, don't specify for creating an invoice.
     */
     int64 amt_paid_sat = 19;
 
     /*
     The amount that was accepted for this invoice, in millisatoshis. This will
-    ONLY be set if this invoice has been settled. We provide this field as if
+    ONLY be set if this invoice has been settled or accepted. We provide this
-    the invoice was created with a zero value, then we need to record what
+    field as if the invoice was created with a zero value, then we need to
-    amount was ultimately accepted. Additionally, it's possible that the sender
+    record what amount was ultimately accepted. Additionally, it's possible that
-    paid MORE that was specified in the original invoice. So we'll record that
+    the sender paid MORE that was specified in the original invoice. So we'll
-    here as well.
+    record that here as well.
     Note: Output only, don't specify for creating an invoice.
     */
     int64 amt_paid_msat = 20;

lnrpc/lightning.swagger.json

@@ -5116,12 +5116,12 @@
         "amt_paid_sat": {
           "type": "string",
           "format": "int64",
-          "description": "The amount that was accepted for this invoice, in satoshis. This will ONLY\nbe set if this invoice has been settled. We provide this field as if the\ninvoice was created with a zero value, then we need to record what amount\nwas ultimately accepted. Additionally, it's possible that the sender paid\nMORE that was specified in the original invoice. So we'll record that here\nas well.\nNote: Output only, don't specify for creating an invoice."
+          "description": "The amount that was accepted for this invoice, in satoshis. This will ONLY\nbe set if this invoice has been settled or accepted. We provide this field\nas if the invoice was created with a zero value, then we need to record what\namount was ultimately accepted. Additionally, it's possible that the sender\npaid MORE that was specified in the original invoice. So we'll record that\nhere as well.\nNote: Output only, don't specify for creating an invoice."
         },
         "amt_paid_msat": {
           "type": "string",
           "format": "int64",
-          "description": "The amount that was accepted for this invoice, in millisatoshis. This will\nONLY be set if this invoice has been settled. We provide this field as if\nthe invoice was created with a zero value, then we need to record what\namount was ultimately accepted. Additionally, it's possible that the sender\npaid MORE that was specified in the original invoice. So we'll record that\nhere as well.\nNote: Output only, don't specify for creating an invoice."
+          "description": "The amount that was accepted for this invoice, in millisatoshis. This will\nONLY be set if this invoice has been settled or accepted. We provide this\nfield as if the invoice was created with a zero value, then we need to\nrecord what amount was ultimately accepted. Additionally, it's possible that\nthe sender paid MORE that was specified in the original invoice. So we'll\nrecord that here as well.\nNote: Output only, don't specify for creating an invoice."
         },
         "state": {
           "$ref": "#/definitions/InvoiceInvoiceState",