message: dont start thread with daemon=True, doesnt work in python2
diff: @@ -251,7 +251,7 @@ class Channel(PacketSink):
  self._printer("receiver thread is exiting: " + traceback.format_exc())
  finally:
  self._channel_broken.set()
  - threading.Thread(target=receiver_thread, daemon=True).start()
  + threading.Thread(target=receiver_thread).start()
  def remote_endpoint_operation(self, endpoint_id, input, expect_ack, output_length):
  if input is None:
  