修复打包发布后，网站白屏bug(#app不能有下一个节点元素)

Author: lang1427

public/index.html

@@ -177,15 +177,15 @@
     <strong>We're sorry but vue-typescript-music doesn't work properly without JavaScript enabled. Please enable it to
       continue.</strong>
   </noscript>
-  <div id="app"></div>
-  <!-- built files will be auto injected -->
   <div id="first-loading">
     <div class="hourglass">
       <div class="hourglass-stand"></div>
       <div class="hourglass-sand"></div>
       <div class="hourglass-stream"></div>
     </div>
   </div>
+  <div id="app"></div>
+  <!-- built files will be auto injected -->
 </body>
 
 </html>