l10n: de.po: translate 241 messages

Translate 241 messages came from git.pot update in 673bfad
(l10n: git.pot: v2.12.0 round 1 (239 new, 15 removed)) and a4d9483
(l10n: git.pot: v2.12.0 round 2 (2 new)).

Signed-off-by: Ralf Thielow <[email protected]>
Acked-by: Phillip Sz <[email protected]>

Author: ralfth