reset _listeningPort and _listening Deferred on teardown

lbrynet/dht/node.py

@@ -159,6 +159,7 @@ class Node(MockKademliaHelper):
         yield self.safe_stop_looping_call(self._change_token_lc)
         if self._listeningPort is not None:
             yield self._listeningPort.stopListening()
+        self._listeningPort = None
 
     def start_listening(self):
         if not self._listeningPort:

lbrynet/dht/protocol.py

@@ -171,6 +171,8 @@ class KademliaProtocol(protocol.DatagramProtocol):
 
     def startProtocol(self):
         log.info("DHT listening on UDP %s:%i", self._node.externalIP, self._node.port)
+        if self._listening.called:
+            self._listening = defer.Deferred()
         self._listening.callback(True)
         return self._ping_queue.start()