status: remove err when marking sub-server as running

Ensure that the sub-server error string is set to an empty string when
marking a sub-server as running. This will be important for the next
commit, which will retry to start the lnd sub-server even if we error
when starting the lnd-client(s), and therefore may mark the lnd
sub-server as running even after we've errored when starting the
lnd-client(s).

Author: ViktorTigerstrom

status/manager.go

@@ -216,6 +216,7 @@ func (s *Manager) SetRunning(name string) {
 	}
 
 	ss.Running = true
+	ss.Err = ""
 	ss.customStatus = ""
 }