Gracefully handle processor releasing issues

OperationalError: disk I/O error
  File "nxdrive/engine/workers.py", line 197, in run
    self._execute()
  File "nxdrive/engine/processor.py", line 495, in _execute
    self.dao.release_state(self.thread_id)
  File "nxdrive/engine/dao/sqlite.py", line 1203, in release_state
    self.release_processor(thread_id)
  File "nxdrive/engine/dao/sqlite.py", line 1209, in release_processor
    c.execute(
  File "nxdrive/engine/dao/sqlite.py", line 162, in execute
    raise exc
  File "nxdrive/engine/dao/sqlite.py", line 155, in execute
    return super().execute(*args, **kwargs)

Thread EXCEPTION