Update ParseWebSocketServer.js (#5860)

* Update ParseWebSocketServer.js

fix wss:// error by requiring 'ws' module, remove uws as it has been deprecated and removed from npm

* Update ParseWebSocketServer.js

* remove uws

src/LiveQuery/ParseWebSocketServer.js

@@ -1,12 +1,8 @@
 import logger from '../logger';
 
 const typeMap = new Map([['disconnect', 'close']]);
-const getWS = function() {
-  try {
-    return require('uws');
-  } catch (e) {
-    return require('ws');
-  }
+const getWS = function(){
+  return require('ws');
 };
 
 export class ParseWebSocketServer {