Bug 1353937 - Expose http server wrapped js object for private apis. r=mcmanus

Slimerjs relies on the hidden _start to create a server with a
port and host.

netwerk/test/httpserver/httpd.js

@@ -739,6 +739,10 @@ nsHttpServer.prototype =
     return this._handler._setObjectState(k, v);
   },
 
+  get wrappedJSObject() {
+    return this;
+  },
+
 
   // NSISUPPORTS