Ignore RuntimeError: wrapped C/C++ object of type QueueManager has been deleted in QueueManager.push_error()

AttributeError: 'NoneType' object has no attribute 'get'
  File "urllib3/connectionpool.py", line 257, in _get_conn
    conn = self.pool.get(block=self.block, timeout=timeout)

ClosedPoolError: HTTPConnectionPool(host='localhost', port=8080): Pool is closed.
(3 additional frame(s) were not displayed)
...
  File "urllib3/connectionpool.py", line 783, in urlopen
    return self.urlopen(
  File "urllib3/connectionpool.py", line 783, in urlopen
    return self.urlopen(
  File "urllib3/connectionpool.py", line 783, in urlopen
    return self.urlopen(
  File "urllib3/connectionpool.py", line 688, in urlopen
    conn = self._get_conn(timeout=pool_timeout)
  File "urllib3/connectionpool.py", line 260, in _get_conn
    raise ClosedPoolError(self, "Pool is closed.")

ConnectionError: HTTPConnectionPool(host='localhost', port=8080): Pool is closed.
(13 additional frame(s) were not displayed)
...
  File "nuxeo/client.py", line 310, in request
    raise self._handle_error(exc)
  File "nuxeo/client.py", line 304, in request
    resp = self._session.request(
  File "requests/sessions.py", line 542, in request
    resp = self.send(prep, **send_kwargs)
  File "requests/sessions.py", line 655, in send
    r = adapter.send(request, **kwargs)
  File "requests/adapters.py", line 519, in send
    raise ConnectionError(e, request=request)

RuntimeError: wrapped C/C++ object of type QueueManager has been deleted
  File "nxdrive/engine/workers.py", line 197, in run
    self._execute()
  File "nxdrive/engine/processor.py", line 367, in _execute
    self._postpone_pair(doc_pair, "CONNECTION_ERROR")
  File "nxdrive/engine/processor.py", line 766, in _postpone_pair
    self.engine.queue_manager.push_error(
  File "nxdrive/engine/queue_manager.py", line 277, in push_error
    self.newError.emit(doc_pair.id)

Thread EXCEPTION