Pass in loop to PluginManager

If `loop` is passed to `MQTTClient`, previously it was not passed down
to `PluginManager`, which could potentially grab a different loop from
`asyncio.get_event_loop()`, resulting in a separate event loop being
created or wrong one being used. Now the `loop` argument is passed down
as expected.

Author: girtsf

hbmqtt/client.py

@@ -112,7 +112,7 @@ def __init__(self, client_id=None, config=None, loop=None):
         # Init plugins manager
         context = ClientContext()
         context.config = self.config
-        self.plugins_manager = PluginManager('hbmqtt.client.plugins', context)
+        self.plugins_manager = PluginManager('hbmqtt.client.plugins', context, loop=self._loop)
         self.client_tasks = deque()
 
     async def connect(self,