Send fewer spam messages in p2p_invalid_messages

Builds on travis are failing because the test node isn't
able to drop all the bad messages sent within the given
timeout. Reduce the number of bad messages we're sending
and increase the timeout to avoid failures on travis.

test/functional/p2p_invalid_messages.py

@@ -72,7 +72,7 @@ def run_test(self):
                 "memory exhaustion. May take a bit...")
 
             # Run a bunch of times to test for memory exhaustion.
-            for _ in range(200):
+            for _ in range(80):
                 node.p2p.send_message(msg_at_size)
 
             # Check that, even though the node is being hammered by nonsense from one
@@ -82,7 +82,7 @@ def run_test(self):
 
             # Peer 1, despite serving up a bunch of nonsense, should still be connected.
             self.log.info("Waiting for node to drop junk messages.")
-            node.p2p.sync_with_ping(timeout=8)
+            node.p2p.sync_with_ping(timeout=30)
             assert node.p2p.is_connected
 
         #