rabbit: Missing to pass parameter timeout to next

Missing to pass parameter 'timeout' to the method '_ensure_publishing'
when publishing a message.

That will cause RPCClient.call unable to pass timeout to the underlying.

Change-Id: I1abc7e9c6f5204fa336f29a94114c18d8b982fcb

oslo_messaging/_drivers/impl_rabbit.py

@@ -1091,7 +1091,8 @@ def topic_send(self, exchange_name, topic, msg, timeout=None, retry=None):
             auto_delete=self.amqp_auto_delete)
 
         self._ensure_publishing(self._publish, exchange, msg,
-                                routing_key=topic, retry=retry)
+                                routing_key=topic, timeout=timeout,
+                                retry=retry)
 
     def fanout_send(self, topic, msg, retry=None):
         """Send a 'fanout' message."""