Revert "update outgoing.headers.host incase the destination does proxying"

This reverts commit 65b7872e.

lib/node-http-proxy/http-proxy.js

@@ -195,8 +195,6 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
   outgoing.path    = req.url;
   outgoing.headers = req.headers;
 
-  if(this.changeOrigin)
-    outgoing.headers.host = this.target.host + (this.target.port == 80 ? '' : ':' + this.target.port)
   //
   // Open new HTTP request to internal resource with will act 
   // as a reverse proxy pass