pytest: fix flake in tests/test_connection.py::test_reconnect_signed

Sometimes, l1 wouldn't receive the msg before l2 hung up, causing
chaos.  What we *actually* want here is to make sure that l1 receives
the msg before closing:

```
        l1.rpc.connect(l2.info['id'], 'localhost', l2.port)
>       l1.rpc.fundchannel(l2.info['id'], CHANNEL_SIZE)

tests/test_connection.py:667: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
contrib/pyln-client/pyln/client/lightning.py:767: in fundchannel
    return self.call("fundchannel", payload)
contrib/pyln-testing/pyln/testing/utils.py:740: in call
    res = LightningRpc.call(self, method, payload, cmdprefix, filter)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <pyln.testing.utils.PrettyPrintingLightningRpc object at 0x7f22112f5450>
method = 'fundchannel'
payload = {'amount': 50000, 'announce': True, 'id': '022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59'}
cmdprefix = None, filter = None

    def call(self, method, payload=None, cmdprefix=None, filter=None):
        """Generic call API: you can set cmdprefix here, or set self.cmdprefix
        before the call is made.
    
        """
        self.logger.debug("Calling %s with payload %r", method, payload)
    
        if payload is None:
            payload = {}
        # Filter out arguments that are None
        if isinstance(payload, dict):
            payload = {k: v for k, v in payload.items() if v is not None}
    
        this_id = self.get_json_id(method, cmdprefix)
        self.next_id += 1
    
        # FIXME: we open a new socket for every readobj call...
        sock = UnixSocket(self.socket_path)
    
        buf = b''
    
        if self._notify is not None:
            # Opt into the notifications support
            self._writeobj(sock, {
                "jsonrpc": "2.0",
                "method": "notifications",
                "id": this_id + "+notify-enable",
                "params": {
                    "enable": True
                },
            })
            # FIXME: Notification schema support?
            _, buf = self._readobj(sock, buf)
    
        request = {
            "jsonrpc": "2.0",
            "method": method,
            "params": payload,
            "id": this_id,
        }
    
        if filter is None:
            filter = self._filter
        if filter is not None:
            request["filter"] = filter
    
        self._writeobj(sock, request)
        while True:
            resp, buf = self._readobj(sock, buf)
            id = resp.get("id", None)
            meth = resp.get("method", None)
    
            if meth == 'message' and self._notify is not None:
                n = resp['params']
                self._notify(
                    message=n.get('message', None),
                    progress=n.get('progress', None),
                    request=request
                )
                continue
    
            if meth is None or id is None:
                break
    
        self.logger.debug("Received response for %s call: %r", method, resp)
        if 'id' in resp and resp['id'] != this_id:
            raise ValueError("Malformed response, id is not {}: {}.".format(this_id, resp))
        sock.close()
    
        if not isinstance(resp, dict):
            raise TypeError("Malformed response, response is not a dictionary %s." % resp)
        elif "error" in resp:
>           raise RpcError(method, payload, resp['error'])
E           pyln.client.lightning.RpcError: RPC call failed: method: fundchannel, payload: {'id': '022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59', 'amount': 50000, 'announce': True}, error: {'code': -1, 'message': 'Disconnected', 'data': {'id': '022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59', 'method': 'openchannel_update'}}
```

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_connection.py

@@ -653,13 +653,12 @@ def test_disconnect_half_signed_v2(node_factory):
 @pytest.mark.openchannel('v2')
 def test_reconnect_signed(node_factory):
     # This will fail *after* both sides consider channel opening.
-    disconnects = ['+WIRE_FUNDING_SIGNED']
+    disconnects = ['<WIRE_FUNDING_SIGNED']
     if EXPERIMENTAL_DUAL_FUND:
-        disconnects = ['+WIRE_COMMITMENT_SIGNED']
+        disconnects = ['<WIRE_COMMITMENT_SIGNED']
 
-    l1 = node_factory.get_node(may_reconnect=True)
-    l2 = node_factory.get_node(disconnect=disconnects,
-                               may_reconnect=True)
+    l1 = node_factory.get_node(may_reconnect=True, disconnect=disconnects)
+    l2 = node_factory.get_node(may_reconnect=True)
 
     l1.fundwallet(2000000)