add: project permit change identifier

app/controllers/projects_controller.rb

@@ -229,7 +229,7 @@ class ProjectsController < ApplicationController
 
   private
   def project_params
-    params.permit(:user_id, :name, :description, :repository_name, :website, :lesson_url, :default_branch,
+    params.permit(:user_id, :name, :description, :repository_name, :website, :lesson_url, :default_branch, :identifier,
                   :project_category_id, :project_language_id, :license_id, :ignore_id, :private)
   end