move drag_info show/hide to page.ready, to avoid flouc

IPython/frontend/html/notebook/static/js/notebooklist.js

@@ -27,8 +27,9 b' var IPython = (function (IPython) {'
 
 
     NotebookList.prototype.bind_events = function () {
-        if (IPython.read_only)
-        {return}
+        if (IPython.read_only){
+            return;
+        }
         var that = this;
         this.element.bind('dragover', function () {
             return false;
@@ -85,9 +86,6 b' var IPython = (function (IPython) {'
             if (!IPython.read_only){
                 // hide delete buttons when readonly
                 this.add_delete_button(item);
-                $('#drag_info').removeClass('hidden');
-            } else {
-                $('#drag_info').remove();
             }
         };
     };

IPython/frontend/html/notebook/static/js/projectdashboardmain.js

@@ -35,8 +35,10 b' $(document).ready(function () {'
     if (IPython.read_only){
         // unhide login button if it's relevant
         $('span#login_widget').removeClass('hidden');
+        $('#drag_info').remove();
     } else {
         $('#new_notebook').removeClass('hidden');
+        $('#drag_info').removeClass('hidden');
     }
     IPython.notebook_list.load_list();