l10n: de.po: translate 825 new messages

Translate 825 new messages came from git.pot update in
cc76011 ("l10n: Update git.pot (825 new, 24 removed messages)").

Signed-off-by: Ralf Thielow <[email protected]>
Reviewed-by: Thomas Rast <[email protected]>
Helped-by: Michael J Gruber <[email protected]>

Author: ralfth