Log gossip rejections due to stale channel_updates at GOSSIP level

This further reduces noise at the TRACE level during initial gossip
sync.

Author: TheBlueMatt

lightning/src/routing/network_graph.rs

@@ -1168,10 +1168,10 @@ impl NetworkGraph {
 			// disable this check during tests!
 			let time = SystemTime::now().duration_since(UNIX_EPOCH).expect("Time must be > 1970").as_secs();
 			if (msg.timestamp as u64) < time - STALE_CHANNEL_UPDATE_AGE_LIMIT_SECS {
-				return Err(LightningError{err: "channel_update is older than two weeks old".to_owned(), action: ErrorAction::IgnoreError});
+				return Err(LightningError{err: "channel_update is older than two weeks old".to_owned(), action: ErrorAction::IgnoreAndLog(Level::Gossip)});
 			}
 			if msg.timestamp as u64 > time + 60 * 60 * 24 {
-				return Err(LightningError{err: "channel_update has a timestamp more than a day in the future".to_owned(), action: ErrorAction::IgnoreError});
+				return Err(LightningError{err: "channel_update has a timestamp more than a day in the future".to_owned(), action: ErrorAction::IgnoreAndLog(Level::Gossip)});
 			}
 		}