[Tails-l10n] [fr](review) 3.2 (testing branch)

Hello, I translate encryption_and_privacy.index.fr.po,
virtual_keyboard.fr.po and known_issues.fr.po.
I also fix a link in known_issues.mdwn.

Please review.

Repo: https://git-tails.immerda.ch/xin/tails/
Branch: translate/testing/3.2
Last Commit: 0e55c53ef777ff82c1456a50c3ce06a3ff76ebba

Cheers.
xin