clean code

packages/app/resource/locales/en_US/translation.json

@@ -1009,7 +1009,6 @@
     "private_legacy_pages": "Private Legacy Pages",
     "cannot_rename_a_title_that_contains_slash": "Cannot rename a title that contains '/'",
     "you_cannot_move_this_page_now": "You cannot move this page now",
-    "forbidden_to_move_target_page": "Forbidden to move to target page",
     "something_went_wrong_with_moving_page": "Something went wrong with moving page"
   },
   "duplicated_page_alert" : {

packages/app/resource/locales/ja_JP/translation.json

@@ -1001,7 +1001,6 @@
     "private_legacy_pages": "旧形式のプライベートページ",
     "cannot_rename_a_title_that_contains_slash": "`/` が含まれているタイトルにリネームできません",
     "you_cannot_move_this_page_now": "現在、このページを移動することはできません",
-    "forbidden_to_move_target_page": "対象のページへの移動は禁止されています",
     "something_went_wrong_with_moving_page": "ページの移動に問題が発生しました"
   },
   "duplicated_page_alert" : {

packages/app/resource/locales/zh_CN/translation.json

@@ -1011,7 +1011,6 @@
     "private_legacy_pages": "私人遗留页面",
     "cannot_rename_a_title_that_contains_slash": "不能重命名包含 ’/' 的标题",
     "you_cannot_move_this_page_now": "你现在不能移动这个页面",
-    "forbidden_to_move_target_page": "禁止移动到该页面",
     "something_went_wrong_with_moving_page": "移动页面时出了问题"
   },
   "duplicated_page_alert" : {