[Tails-l10n] [fr] (review) wiki/src/doc/about/openpgp_keys.f…

Hello, I don't update all the page because I don't know how to translate
things like "air-gapped" and "secret key stubs".

I think I have found an error in the english version :
"Expiration date: same as the subkey."
It should be "same as the primary key.", right ?

Please review.

Repo : https://git-tails.immerda.ch/xin/tails/
Branch : translate/openpgp_keys
Last Commit : dee562c4fd5c0d354a2a3e8f254f91787afee836

Cheers.
xin