Error raised when project's lock expired before unlocking #55
Description
When locking of projects is enabled, and the whole process takes a bit longer to the point that the lock expires (~5 min currently I believe), unlocking in ProjectPadlock.unlock() will fail with a ClientError which is further propagated:
ClientError: The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
This is because the MM server has removed the transaction, so the URL does not exist anymore.
We should instead just log that the lock has expired and try to continue.