Add i18n for message in editor pop-up

config/locales/en.yml

@@ -11,6 +11,7 @@ en:
   back: Back
   browse: Browse
   cancel: Cancel
+  cant_empty_star: Cannot be empty (*)
   create_fail: Creation failed
   create: Create
   delete: Delete

config/locales/zh_tw.yml

@@ -8,6 +8,7 @@ zh_tw:
   back: 回上一步
   browse: 選擇檔案
   cancel: 取消
+  cant_empty_star: 不能為空 (*)
   create: 新增
   create_fail: 創建失敗
   delete: 刪除