Prevent Watchdog error on account deletion

2018-08-10 15:28 python[32172] (FSEvents.framework) FSEventStreamStop(): failed assertion 'streamRef != NULL'
2018-08-10 15:28 python[32172] (FSEvents.framework) FSEventStreamInvalidate(): failed assertion 'streamRef != NULL'
2018-08-10 15:28 python[32172] (FSEvents.framework) FSEventStreamRelease(): failed assertion 'streamRef != NULL'
2018-08-10 15:28:02 32172 123145423323136 ERROR    nxdrive.engine.watcher.local_watcher Cannot stop FS root observer
Traceback (most recent call last):
  File "engine/watcher/local_watcher.py", line 99, in _execute
    self._interact()
  File "engine/workers.py", line 118, in _interact
    raise ThreadInterrupt()
nxdrive.exceptions.ThreadInterrupt

During handling of the above exception, another exception occurred:
ValueError: PyCapsule_GetPointer called with invalid PyCapsule object
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
  File "engine/watcher/local_watcher.py", line 652, in _stop_watchdog
    self._root_observer.stop()
  File ".../watchdog/utils/__init__.py", line 93, in stop
    self.on_thread_stop()
  File ".../watchdog/observers/api.py", line 360, in on_thread_stop
    self.unschedule_all()
  File ".../watchdog/observers/api.py", line 356, in unschedule_all
    self._clear_emitters()
  File ".../watchdog/observers/api.py", line 234, in _clear_emitters
    emitter.stop()
  File ".../watchdog/utils/__init__.py", line 93, in stop
    self.on_thread_stop()
  File ".../watchdog/observers/fsevents.py", line 62, in on_thread_stop
    _fsevents.remove_watch(self.watch)
SystemError: <built-in function remove_watch> returned a result with an error set