EnginePort: TypeError: %d format: a number is required, not NoneType

[thiell]

Saw the following problem in a cancelled test:

  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/runner/work/clustershell/clustershell/lib/ClusterShell/Task.py", line 393, in _thread_start
    self._terminate(kill=True)
  File "/home/runner/work/clustershell/clustershell/lib/ClusterShell/Task.py", line 963, in _terminate
    self._engine.clear(clear_ports=kill)
  File "/home/runner/work/clustershell/clustershell/lib/ClusterShell/Engine/Engine.py", line 534, in clear
    self._remove(client, True, did_timeout)
  File "/home/runner/work/clustershell/clustershell/lib/ClusterShell/Engine/Engine.py", line 483, in _remove
    client._close(abort=abort, timeout=did_timeout)
  File "/home/runner/work/clustershell/clustershell/lib/ClusterShell/Worker/EngineClient.py", line 518, in _close
    LOGGER.debug('%r: dropped msg: %s', self, pmsg.get())
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 1162, in debug
    self._log(DEBUG, msg, args, **kwargs)
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 1293, in _log
    self.handle(record)
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 1303, in handle
    self.callHandlers(record)
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 1343, in callHandlers
    hdlr.handle(record)
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 766, in handle
    self.emit(record)
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/site-packages/nose/plugins/logcapture.py", line 82, in emit
    self.buffer.append(self.format(record))
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 741, in format
    return fmt.format(record)
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 465, in format
    record.message = record.getMessage()
  File "/opt/hostedtoolcache/Python/2.7.18/x64/lib/python2.7/logging/__init__.py", line 329, in getMessage
    msg = msg % self.args
  File "/home/runner/work/clustershell/clustershell/lib/ClusterShell/Worker/EngineClient.py", line 503, in __repr__
    id(self), fd_in, fd_out)
TypeError: %d format: a number is required, not NoneType