Validators translations (fi)

[mathewrapid]

The Finnish validators translation (https://github.com/FriendsOfSymfony/FOSUserBundle/blob/master/Resources/translations/validators.fi.yml) is missing the "password.mismatch".

The Finnish counterpart could be "Salasanat eivät täsmää"

[stof]

Pease submit a pull request

[mathewrapid]

#1444