the problem is in : when i follow the symfony documentation:https://github.com/FriendsOfSymfony/FOSUserBundle/blob/master/Resources/doc/index.md in step a) Doctrine ORM User class i have created a folder doctrine contains User.orm.yml:
src/Acme/UserBundle/Resources/config/doctrine/User.orm.yml
Acme\UserBundle\Entity\User: type: entity table: fos_user id: id: type: integer generator: strategy: AUTO
this file crush any update in your entities and update of your database shemea .The solution is to delete this folder.