解决polyfill冲突

src/index.ejs

@@ -4,7 +4,6 @@
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>Dva Demo</title>
-  <script src="https://cdn.polyfill.io/v2/polyfill.min.js"></script>
   <script src="https://cdn.bootcss.com/babel-polyfill/6.26.0/polyfill.min.js"></script>
   <!--<link rel="stylesheet" href="/index.css" />-->
 </head>