remove bind polyfill from namespace_select.js

app/assets/javascripts/namespace_select.js

@@ -2,11 +2,9 @@
 /* global Api */
 
 (function() {
-  var bind = function(fn, me) { return function() { return fn.apply(me, arguments); }; };
-
   window.NamespaceSelect = (function() {
     function NamespaceSelect(opts) {
-      this.onSelectItem = bind(this.onSelectItem, this);
+      this.onSelectItem = this.onSelectItem.bind(this);
       var fieldName, showAny;
       this.dropdown = opts.dropdown;
       showAny = true;