pscli can't stop peerswapd when LND is down

If LND is shut down while `peerswapd` is running, `pscli` seems to be unable to stop `peerswapd`:

```
$ ps aux | grep peerswapd
user 2605252 0.2 0.0 1843616 22016 pts/6 Sl 15:11 0:00 ./builds/peerswap/out/peerswapd
user 2605296 0.0 0.0 6024 2008 pts/6 S+ 15:11 0:00 grep --color=auto peerswapd

$ ./builds/peerswap/out/pscli stop
2023/01/12 15:12:01 rpc error: code = Unavailable desc = connection error: desc = "transport: Error while dialing dial tcp 127.0.0.1:42069: connect: connection refused"
```

This might be related to the bug where many (zombie?) peerswap processes are running simultaneously somehow?