This doesn't work anymore and thus breaks the installation leaving a
broken `/var/lib/nextcloud`.
It isn't a big deal since we set this value in the override config
before, so the correct table-prefix is still used. In order to confirm
that, I decided to add a custom prefix to the basic test.
(cherry picked from commit eaeb4fe04ee5a5ffae4f7dc03d3f072d59d80337)
0db1a5ee44