move setting nb.kernelselector inside kernelselector itself

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

@@ -11,6 +11,7 @@ define([
     var KernelSelector = function(selector, notebook) {
         this.selector = selector;
         this.notebook = notebook;
+        this.notebook.set_kernelselector(this);
         this.events = notebook.events;
         this.current_selection = null;
         this.kernelspecs = {};

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

@@ -113,7 +113,6 @@ require([
     notification_area.init_notification_widgets();
     var kernel_selector = new kernelselector.KernelSelector(
         '#kernel_selector_widget', notebook);
-    notebook.set_kernelselector(kernel_selector);
 
     $('body').append('<div id="fonttest"><pre><span id="test1">x</span>'+
                      '<span id="test2" style="font-weight: bold;">x</span>'+