The "Self Check" menu essentially runs the collation check that is also
performed at startup, and displays the results. This is only a thing for
MariaDB/MySQL and MSSQL. As such, the menu item should only be available
for these database types.
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
(cherry picked from commit 0ca118fdc3c39c0e7adf9285e074e5878a0ca1c1)
