Update perform.js

plugins/do/do-http-request/perform.js

 var vm = require('vm');
 var request = require('request').defaults({ encoding: null });
 
-function execute_function(context,output,response){
+function perform_function(context,request,response){
   var job_id = context.jobconfig.job_id;
   var transaction_id = context.transaction.id;
   var param = context.jobconfig.data_out.param;
-  var data = context.output.data;
-  var meta = context.output.meta;
+  var data = context.request.data;
+  var meta = context.request.meta;
 
   var output_type = 'text';
   var url = param.url;