l10n: de.po: translate 9 new messages

Translate 9 new messages came from git.pot update in a4156d20
(l10n: git.pot: v2.5.0 round 2 (9 new, 5 removed)).
Signed-off-by: NRalf Thielow <ralf.thielow@gmail.com>
Acked-by: NPhillip Sz <phillip.szelat@gmail.com>