fix `Notification is not defined` on Android Webview or under ios16.4

Kairlec

2023-04-23 ea3f899593f47c1c6fe708495af0a091a3c73d5f

 web_src/index.html

@@ -15,5 +15,6 @@
    <script type="text/javascript" src="./static/js/ZLMRTCClient.js"></script>
    <script type="text/javascript" src="./static/js/config.js"></script>
    <div id="app"></div>

  </body>
</html>