refactor(LoadMore): 修改 bind:tap 为 mut-bind:tap

Author: juzi214032

src/loadmore/index.wxml

@@ -1,6 +1,6 @@
 <!-- 内容插槽 -->
 <slot name="content" />
-<view bindtap="onLoadmore" wx:if="{{show}}">
+<view mut-bind:tap="onLoadmore" wx:if="{{show}}">
   <view wx:if="{{custom && type==='end'}}">
     <slot name="end" />
   </view>