fix wrong nb of related objects in msg when deleting an object
fix wrong nb of related objects in msg when deleting an object

lino-framework/welfare,lino-framework/welfare,lino-framework/welfare,lsaffre/lino-welfare,lsaffre/lino-welfare,lsaffre/lino-welfare,lsaffre/lino-welfare,lsaffre/lino-welfare,lino-framework/welfare,lino-framework/welfare