change conf security

models/res_config.py

@@ -14,10 +14,10 @@ class ProjectLFConfiguration(models.TransientModel):
 
     @api.multi
     def set_default_lf_tarif_jour(self):
-        Values = self.env['ir.values'].sudo()
-        Values.set_default('project.config.settings', 'lf_tarif_jour', self.lf_tarif_jour)
+        return self.env['ir.values'].sudo().set_default(
+            'project.config.settings', 'lf_tarif_jour', self.lf_tarif_jour)
 
     @api.multi
     def set_default_alias_prefix(self):
-        Values = self.env['ir.values'].sudo()
-        Values.set_default('project.config.settings', 'lf_alias_prefix', self.lf_alias_prefix)
\ No newline at end of file
+        return self.env['ir.values'].sudo().set_default(
+            'project.config.settings', 'lf_alias_prefix', self.lf_alias_prefix)
\ No newline at end of file