lock.is_owner() does not work

[ricpruss]

Looking at the cause for this.
await self.pool_or_conn.get(self.key) returns a string
and self._token.encode() is a b''

The fix is to drop the .encode() i.e new code is.
async def is_owner(self) -> bool:
"""Determine if the instance is the owner of the lock"""
return (
await self.pool_or_conn.get(self.key)
) == self._token # pylint: disable=no-member