brontide: increase logging when processing gossip msgs

We add logging to we can draw conclusions how long the processing
of gossip message last and potentially see whether the syncer
buffer channel size is a bottleneck in processing.

discovery/gossiper.go

@@ -860,8 +860,6 @@ func (d *AuthenticatedGossiper) stop() {
 func (d *AuthenticatedGossiper) ProcessRemoteAnnouncement(ctx context.Context,
 	msg lnwire.Message, peer lnpeer.Peer) chan error {
 
-	log.Debugf("Processing remote msg %T from peer=%x", msg, peer.PubKey())
-
 	errChan := make(chan error, 1)
 
 	// For messages in the known set of channel series queries, we'll