去掉警告

pages/welfareMall/index/index.wxml

@@ -11,7 +11,7 @@
 
     </swiper>
     <view class="dots">
-      <block wx:for="{{bannerList}}" wx:key>
+      <block wx:for="{{bannerList}}" wx:key="index">
         <view class="dot{{index == currentSwiper ? ' active_dot' : ''}}"></view>
       </block>
     </view>