Update README.md

docs/README.md

@@ -17,7 +17,7 @@ pageClass: custom-page-class
     <div class="flex-img-group-view">
       <a href="//hellouniappx.dcloud.net.cn/" target="_blank" class="clear-style barcode-view">
         <div class="barcode-img-box">
-          <img src="https://web-assets.dcloud.net.cn/unidoc/zh/uni-app-x/hello-uniappx-qrcode.png" width="160" />
+          <img src="https://qiniu-web-assets.dcloud.net.cn/unidoc/zh/uni-app-x/hello-uniappx-qrcode.png" width="160" />
         </div>
         <b>Android版(uni-app x)</b>
       </a>