Notebook.delete should take no args.

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

@@ -1839,7 +1839,7 b' var IPython = (function (IPython) {'
         $.ajax(url, settings);
     };
 
-    Notebook.prototype.delete = function (nbname) {
+    Notebook.prototype.delete = function () {
         var that = this;
         var settings = {
             processData : false,