null tracebacks

Author: nakula

lib/server.js

@@ -122,7 +122,7 @@ exports.Server = function Server(bsClient, workers) {
       if (query == null) {
         console.log("[%s] Null response from remote Browser", request.headers['x-browser-string']);
       } else {
-      if (query.tracebacks.length > 0) {
+      if (query.tracebacks && query.tracebacks.length > 0) {
         console.log("Tracebacks:");
         query.tracebacks.forEach(function (traceback) {
           console.log(traceback);