fix(ui): use const for wsProtocol, lint

Author: psychedelicious

invokeai/frontend/web/src/services/events/middleware.ts

@@ -12,8 +12,8 @@ import { socketSubscribed, socketUnsubscribed } from './actions';
 
 export const socketMiddleware = () => {
   let areListenersSet = false;
-  
-  let wsProtocol = window.location.protocol === 'https:' ? 'wss' : 'ws';
+
+  const wsProtocol = window.location.protocol === 'https:' ? 'wss' : 'ws';
   let socketUrl = `${wsProtocol}://${window.location.host}`;
 
   const socketOptions: Parameters<typeof io>[0] = {