Fixed the missing sessions table after updating to v0.3.9.
- With v0.3.9, we introduced the sessions table to store the session in the database instead of the files. But when you used the update system in the web interface to update mosparo, the session was required before executing the database update. This means you ended in an error 500 because the sessions table did not exist while it was needed to complete the update functionality. With this release, the session handler cannot load data from the sessions table if the update is incomplete.