address PR feedback

IPython/html/static/notebook/js/notebook.js

@@ -59,7 +59,7 @@ var IPython = (function (IPython) {
         this.create_elements();
         this.bind_events();
         this.save_notebook = function() { // don't allow save until notebook_loaded
-            this.save_notebook_error(null, null, "Notebook was not fully loaded.");
+            this.save_notebook_error(null, null, "Load failed, save is disabled");
         };
     };
 

IPython/html/static/notebook/js/notificationarea.js

@@ -189,7 +189,7 @@ var IPython = (function (IPython) {
             nnw.set_message("Notebook saved",2000);
         });
         $([IPython.events]).on('notebook_save_failed.Notebook', function (evt, xhr, status, data) {
-            nnw.set_message("Notebook save failed:" + data);
+            nnw.set_message(data || "Notebook save failed");
         });
         
         // Checkpoint events