Loopd becomes unresponsive after some time

Hey!

After some time (we have not measured how much yet), our loop is having issues doing loop outs, getinfo breaks as in the log below:
```
lnd:/# loop getinfo
[loop] rpc error: code = Unknown desc = sql: Scan error on column index 20, name "publication_deadline": unsupported Scan, storing driver.Value type string into type *time.Time
```

Additionally, invoking loop out gives this error:
```
cltv delta below minimum: 98
```

It somehow resolves if we kill `loopd` and some swaps got broadcast onchain

**System information**

Versions:
LND 0.17.5 and loop 0.27.1 for amd64 linux containers on kubernetes (AWS)

Start with the loopd behavior described in the report and reproduce the failure using `loop getinfo` and a loop-out request after the daemon has run for some time. Inspect the SQL scan error for `publication_deadline` alongside the `cltv delta below minimum` message. Done means loopd remains responsive and both operations work without requiring a restart.

Written by the indexing model from the issue text.