Typo in german security & setup warnings – ooc instead of occ

[MarcMichalsky]

There is a typo in the german security & setup warnings. It's the warning for missing indices in the database.

It should be "occ" instead of "ooc".

[nextcloud-bot]

GitMate.io thinks possibly related issues are #3002 (Strange "Security & setup warnings" on nginx), #4596 (Consider about showing SQLite info in "Security & setup warnings" instead of "Tips & tricks" ), #10220 (Unnecessary Security & setup warnings), #5044 (Security & setup warnings > Which php.ini to edit?), and #9250 (Security & setup warnings fails with 2 times the same header).

[rullzer]

Already fixed on transifex. Should be synced soon and in beta4