fix incorrect handling of closure

worker.js

@@ -35,10 +35,11 @@ module.exports.create = function (opts) {
           return;
         }
 
-        var err = new Error("___MESSAGE___");
         process.send({ type: 'LE_REQUEST', domain: domain, options: results.options, certs: results.certs });
 
         process.on('message', function (msg) {
+          var err = new Error("___MESSAGE___");
+
           log(opts.debug, 'Message from master');
           log(opts.debug, msg);