Sockets are kept around after run if die encountered

[asmartin]

In #46 syncoid errors out with a call to die. In this case, it does not clean up the socket in /tmp, so this file gets left behind. Would it be possible to add an END block that cleans up $socket? Thanks!

[jimsalterjrs]

This should no longer be a problem, because instead of ControlPersist=yes I'm now using ControlPersist=1m, which will cause the mux channel to die all by itself after no activity.