l10n: de.po: translate 123 new messages

Translate 123 new messages came from git.pot update in df0617b
(l10n: git.pot: v2.6.0 round 1 (123 new, 41 removed)).

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

Author: ralfth