connectd: force our own channel gossip to more peers

Large nodes were not always getting their own channel gossip out
reliably.  The number of peers we spam our own channel gossip to
is limited to save large nodes on startup, but this should be
relaxed slightly to ensure propagation.

Changelog-Fixed: Own-channel gossip is broadcast to more peers on connect.

connectd/multiplex.c

@@ -212,7 +212,7 @@ static struct oneshot *gossip_stream_timer(struct peer *peer)
 }
 
 /* Statistically, how many peers to we tell about each channel? */
-#define GOSSIP_SPAM_REDUNDANCY 5
+#define GOSSIP_SPAM_REDUNDANCY 50
 
 /* BOLT #7:
  * A node: