docs: fix cdn link (#8023)

src/empty/README.md

@@ -36,7 +36,7 @@ Use the image prop to display different placeholder images.
 ```html
 <van-empty
   class="custom-image"
-  image="https://img.yzcdn.cn/vant/leaf.jpg"
+  image="https://img01.yzcdn.cn/vant/leaf.jpg"
   description="Description"
 />
 

src/empty/README.zh-CN.md

@@ -42,7 +42,7 @@ Empty 组件内置了多种占位图片类型，可以在不同业务场景下
 ```html
 <van-empty
   class="custom-image"
-  image="https://img.yzcdn.cn/vant/custom-empty-image.png"
+  image="https://img01.yzcdn.cn/vant/custom-empty-image.png"
   description="描述文字"
 />
 

src/empty/demo/index.vue

@@ -20,7 +20,7 @@
   <demo-block :title="t('customImage')">
     <van-empty
       class="custom-image"
-      image="https://img.yzcdn.cn/vant/custom-empty-image.png"
+      image="https://img01.yzcdn.cn/vant/custom-empty-image.png"
       :description="t('description')"
     />
   </demo-block>

src/empty/test/__snapshots__/demo.spec.js.snap

@@ -79,7 +79,7 @@ exports[`should render demo and match snapshot 1`] = `
 <div>
   <div class="van-empty custom-image">
     <div class="van-empty__image">
-      <img src="https://img.yzcdn.cn/vant/custom-empty-image.png">
+      <img src="https://img01.yzcdn.cn/vant/custom-empty-image.png">
     </div>
     <p class="van-empty__description">
       Description