Flitter-auth logout should call central logout method

app/controllers/auth/Forms.controller.js

@@ -33,6 +33,11 @@ class Forms extends FormController {
             next_destination: '/',
         })
     }
+
+    async logout_provider_clean_session(req, res, next) {
+        await req.user.logout(req)
+        return next()
+    }
 }
 
 module.exports = exports = Forms