PeerManager: bump the read pause limit

...to make sure we can still get channel messages out after enqueuing some big gossip messages.

lightning/src/ln/peer_handler.rs

@@ -310,7 +310,7 @@ const FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO: usize = 2;
 /// we have fewer than this many messages in the outbound buffer again.
 /// We also use this as the target number of outbound gossip messages to keep in the write buffer,
 /// refilled as we send bytes.
-const OUTBOUND_BUFFER_LIMIT_READ_PAUSE: usize = 10;
+const OUTBOUND_BUFFER_LIMIT_READ_PAUSE: usize = 12;
 /// When the outbound buffer has this many messages, we'll simply skip relaying gossip messages to
 /// the peer.
 const OUTBOUND_BUFFER_LIMIT_DROP_GOSSIP: usize = OUTBOUND_BUFFER_LIMIT_READ_PAUSE * FORWARD_INIT_SYNC_BUFFER_LIMIT_RATIO;