Fix that the weekly backup process (using pgdump) can result in "dangling" db connections, which stay alive forever (show as "active" in session-manager in dbeaver), and which prevent schema changes and such until terminated

I do not currently know what causes the pgdump connections to become "dangling" like this... perhaps it's due to a crash of the app-server while the SQL query in the getPGDump graphql endpoint is being run.