Update user.class.php

String translated twice
Merge pull request #1483 from FHenry/3.5

3.5
delete extrafield on delete invoice
Merge branch '3.5' of git@github.com:Dolibarr/dolibarr.git into 3.5
Merge branch '3.5' of https://github.com/Dolibarr/dolibarr.git into 3.5