Remove unused function and argument

I removed the unused function and (function)argument in code

Change-Id: Ib7afa5d868c3c7769f53e45c270850e4c3370f86

watcher/applier/rpcapi.py

@@ -63,10 +63,3 @@ class ApplierAPI(messaging_core.MessagingCore):
         return self.client.call(
             context.to_dict(), 'launch_action_plan',
             action_plan_uuid=action_plan_uuid)
-
-    def event_receive(self, event):
-        try:
-            pass
-        except Exception as e:
-            LOG.exception(e)
-            raise