Correction of the french translation according to /u/Moldu

I fixed the rest in addition to https://github.com/dogecoin/dogecoin.com/pull/49

https://www.reddit.com/r/dogecoin/comments/2i6gi3/dogecoincom_goes_international/ckzmgaj
Merge pull request #51 from Kirvx/patch-2

Correction of the french translation according to /u/Moldu