readd something, unless there is a reason it got removed in [7706]

src/common/xmpp/dispatcher_nb.py

@@ -135,6 +135,7 @@ class Dispatcher(PlugIn):
 				self._owner.Connection.disconnect()
 				return 0
 		except ExpatError:
+			sys.exc_clear()
 			self.DEBUG('Invalid XML received from server. Forcing disconnect.', 'error')
 			self._owner.Connection.pollend()
 			return 0