zmq test: speedup test by whitelisting peers (immediate tx relay)

Speeds up the zmq test roughly by a factor of 2x (~20 sec. instead of
~40 sec.) and also avoids timeouts on the synchronization methods
(sync_mempool() / sync_blocks()) that happened with a slight chance.
This is due to the fact that there is no upper bound on the trickle
relay time, so even the default of 60s is sometimes too low. Fixed by
enabling immediate tx relay on node1.

Author: theStack

test/functional/interface_zmq.py

@@ -67,6 +67,9 @@ def set_test_params(self):
         self.num_nodes = 2
         if self.is_wallet_compiled():
             self.requires_wallet = True
+        # This test isn't testing txn relay/timing, so set whitelist on the
+        # peers for instant txn relay. This speeds up the test run time 2-3x.
+        self.extra_args = [["[email protected]"]] * self.num_nodes
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_py3_zmq()
@@ -93,7 +96,8 @@ def setup_zmq_test(self, services, *, recv_timeout=60, sync_blocks=True):
             socket = self.ctx.socket(zmq.SUB)
             subscribers.append(ZMQSubscriber(socket, topic.encode()))
 
-        self.restart_node(0, ["-zmqpub%s=%s" % (topic, address) for topic, address in services])
+        self.restart_node(0, ["-zmqpub%s=%s" % (topic, address) for topic, address in services] +
+                             self.extra_args[0])
 
         for i, sub in enumerate(subscribers):
             sub.socket.connect(services[i][1])