Change the address in the canned db: it seems we won the lottery and
l1 connected, and got an error!
```
E ValueError:
E Node errors:
E - lightningd-1: had warning messages
E Global errors:
...
lightningd-1: 2021-04-07T02:44:53.579Z DEBUG 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-channeld-chan#1: peer_out WIRE_CHANNEL_REESTABLISH
lightningd-1: 2021-04-07T02:44:53.579Z DEBUG 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-channeld-chan#1: peer_in WIRE_GOSSIP_TIMESTAMP_FILTER
lightningd-1: 2021-04-07T02:44:53.580Z DEBUG 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-channeld-chan#1: peer_in WIRE_ERROR
lightningd-1: 2021-04-07T02:44:53.580Z INFO 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-chan#1: Peer transient failure in CHANNELD_NORMAL: channeld WARNING: error channel fdeb1ea12e02aa043f66ba581e969a1882d21142b19429995c6733bb71070bb6: Multiple channels unsupported
lightningd-1: 2021-04-07T02:44:53.580Z DEBUG 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-chan#1: Will try reconnect in 60 seconds
```
So I changed the port in the db to "1" which will never succeed:
```
sqlite> .dump peers
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE peers ( id INTEGER, node_id BLOB UNIQUE, address TEXT, PRIMARY KEY (id));
INSERT INTO peers VALUES(1,X'022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59','127.0.0.1:38723');
COMMIT;
sqlite> UPDATE peers SET address="127.0.0.1:1"
...> ;
sqlite> .dump peers
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE peers ( id INTEGER, node_id BLOB UNIQUE, address TEXT, PRIMARY KEY (id));
INSERT INTO peers VALUES(1,X'022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59','127.0.0.1:1');
COMMIT;
sqlite>
```
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
the way we use PSBTs to sign things requires that we have the
scriptpubkey available on the utxo so we can populate the witness-utxo
field with it.
this causes problems if we don't already have the scriptpubkey cached in
the database, as in *some* cases we require a round trip to the HSM to
populate them
to get over this hump, we backfill any and all missing scriptpubkey
information for the utxo's that we hold in our wallet.
this will allow us to clean up the NULL handling of missing
scriptpubkeys.
We erase peer data after the last channel close transaction for that
peer is 100 blocks deep. We were failing to finish the migration because
the peer_id lookup on these was failing.
Now we ignore any channel with a null peer_id.
Fixes#3768
We use a database snapshot with 3 channels -- two of which have HTLCs
dangling and one is an initial open channel tx in the 'old' tx hex
format in last_tx and confirm that they are successfully updated to PSBT
format on start.
