l10n: de.po: translate 2 new, 3 fuzzy messages

Translate 2 new and 3 fuzzy messages came from git.pot update
in 75f7b4b (l10n: Update git.pot (5 new, 3 removed messages)).

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

Author: Ralf Thielow