Release our lock if we have one

def _release_lock(self):
        """Release our lock if we have one"""
        if not self._has_lock():
            return

        # if someone removed our file beforhand, lets just flag this issue
        # instead of failing, to make it more usable.
        lfp = self._lock_file_path()
        try:
            # on bloody windows, the file needs write permissions to be removable.
            # Why ...
            if os.name == 'nt':
                os.chmod(lfp, 0777)
            # END handle win32
            os.remove(lfp)
        except OSError:
            pass
        self._owns_lock = False