add flag to socketio, hope it will improve firefox compatibility

app/static/js/nopaque/main.js

@@ -1,7 +1,7 @@
 class AppClient {
   constructor(currentUserId) {
     if (currentUserId) {
-      this.socket = io({transports: ['websocket']});
+      this.socket = io({transports: ['websocket'], upgrade: false});
       this.users = {};
       this.users.self = this.loadUser(currentUserId);
       this.users.self.eventListeners.job.addEventListener((eventType, payload) => this.jobEventHandler(eventType, payload));