[Tails-l10n] (review)[de] 2.5 release notes

Hi,
I translated the release notes for 2.5. I also stumbled upon an
untranslated string in the 2.4 release notes, I added those changes to
this branch, too.

Please review:
https://gitlab.com/spriver/tails.git
branch: de_tails_25
HEAD commit: fb28c29 Initial translation

Affected files:
wiki/src/news/version_2.4.de.po
wiki/src/news/version_2.5.de.po


Cheers!
spriver