如果是xhr,不走pipe

@@ -57,7 +57,7 @@ module.exports = function(proxyRoute) {
       logger.log('info','grayroute: request options: %j',options,{});
 
       //发起代理请求
-      if(req.headers['accept'].indexOf('text/html')>-1) { 
+      if(req.headers['accept'].indexOf('text/html')>-1||req.xhr) { 
         request(options,function(err,res,body) {
           if(err) {
             logger.log('error','grayroute: request error:',err);