[jio] Fix XMLHttpRequest global

sinon now correctly replace it only on demand.

src/node/jio-compat.js

@@ -220,8 +220,8 @@
 
 }(window, WeakMap, ArrayBuffer, Uint8Array));
 
-var XMLHttpRequest = global.XMLHttpRequest || module.exports,
-  Blob = window.Blob,
+global.XMLHttpRequest = module.exports;
+var Blob = window.Blob,
   atob = window.atob,
   btoa = window.btoa,
   FileReader = window.FileReader,

test/node/node-require.js

@@ -21,15 +21,14 @@
 (function (require, global, Object) {
   "use strict";
 
-  var sinon = require('./sinon-require'),
-    jIO;
-  global.sinon = sinon;
-  global.XMLHttpRequest = sinon.FakeXMLHttpRequest;
-
-  jIO = require('../../dist/jio-latest-node');
+  var sinon,
+    jIO = require('../../dist/jio-latest-node');
   global.jIO = jIO;
   Object.keys(jIO.node_env).forEach(function (key) {
     global[key] = jIO.node_env[key];
   });
 
+  sinon = require('./sinon-require');
+  global.sinon = sinon;
+
 }(require, global, Object));