Make it match the latest react-rails render context

Author: zetachang

spec/reactive-ruby/component_loader_spec.rb

@@ -5,7 +5,6 @@
   GLOBAL_WRAPPER = <<-JS
     var global = global || this;
     var self = self || this;
-    var window = window || this;
     var console = {
       warn: function(s) {  }
     };