sync of french translation. from top to line 1229

 Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     |no
| Applies to    | 2.5
| Fixed tickets | 

i have upgraded the french page about security from top to about line 1200.

Some text are not yet translated but put in place. Diffing was a big task. 

Do i need to ask a pull request for the master branch too ? 
en fait j'ai ajouté les blocs qui manquaient. Il faudrait continuer cette mise à jour ultérieurement.