s3: Merge French translation for pam_winbind after review

s3: Merge French translation for pam_winbind after review

- some wording improvements ("user" is not "usager" but "utilisateur"
- gender neutrality changes:
  by rewording:  ("vous n'êtes pas autorisé" --> "vous n'avez pas
  l'autorisation")
- bad translation corrections: "valide"-->"valable" (a very common
  false friend)
- and several changes we consider to be improvements, mostly because
  they are common wording in computing translations in French

Signed-off-by: Lars Müller <lars@samba.org>