discovery: fix log for adding new gossip syncers

In this commit, we fix the logging when adding new gossip syncers. The
old log would log the byte array, rather than the byte slice. We fix
this by slicing before logging.

discovery/gossiper.go

@@ -1233,7 +1233,7 @@ func (d *AuthenticatedGossiper) InitSyncState(syncPeer lnpeer.Peer, recvUpdates
 	}
 
 	log.Infof("Creating new gossipSyncer for peer=%x",
-		nodeID)
+		nodeID[:])
 
 	syncer := newGossiperSyncer(gossipSyncerCfg{
 		chainHash:       d.cfg.ChainHash,