pytest: fix flake in test_gossip_force_broadcast_channel_msgs

We can get more gossip_filter messages now.  And we can also go over max-messages,
so increase that too.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tests/test_gossip.py

@@ -2309,7 +2309,7 @@ def test_gossip_force_broadcast_channel_msgs(node_factory, bitcoind):
                             '--no-gossip',
                             '--hex',
                             '--network={}'.format(TEST_NETWORK),
-                            '--max-messages={}'.format(7),
+                            '--max-messages={}'.format(10),
                             '--timeout-after={}'.format(120),
                             '{}@localhost:{}'.format(l1.info['id'], l1.port)],
                            check=True,
@@ -2319,10 +2319,11 @@ def test_gossip_force_broadcast_channel_msgs(node_factory, bitcoind):
     for l in lines:
         tally[types[l[0:4]]] += 1
 
+    assert tally['gossip_filter'] >= 1
     del tally['query_short_channel_ids']
     del tally['query_channel_range']
     del tally['ping']
+    del tally['gossip_filter']
     assert tally == {'channel_announce': 1,
                      'channel_update': 3,
-                     'node_announce': 1,
-                     'gossip_filter': 1}
+                     'node_announce': 1}