remove unused id declaration

src/client/js/app.jsx

@@ -31,7 +31,6 @@ import BookmarkList from './components/PageList/BookmarkList';
 import LikerList from './components/User/LikerList';
 import Fab from './components/Fab';
 import PersonalSettings from './components/Me/PersonalSettings';
-import UserContentsLinks from './components/UserContentsLinks';
 import GrowiSubNavigation from './components/Navbar/GrowiSubNavigation';
 import GrowiSubNavigationSwitcher from './components/Navbar/GrowiSubNavigationSwitcher';
 
@@ -114,7 +113,6 @@ if (pageContainer.state.pageId != null) {
 
     'recent-created-icon': <RecentlyCreatedIcon />,
     'user-bookmark-icon': <BookmarkIcon />,
-    'grw-user-contents-links': <UserContentsLinks />,
   });
 }
 if (pageContainer.state.creator != null) {