fix: two-way data binding model

pages/my/my.wxml

@@ -35,7 +35,7 @@
         <button class="avatar-wrapper" open-type="chooseAvatar" bind:chooseavatar="onChooseAvatar">
           <image class="avatar" src="{{avatarUrl}}"></image>
         </button> 
-        <input type="nickname" mode:value="{{nickname}}" class="weui-input nickname-input" placeholder="请输入昵称"/>
+        <input type="nickname" model:value="{{nickname}}" class="weui-input nickname-input" placeholder="请输入昵称"/>
         <button size="mini" class="confirm itt-btn" bindtap="handleConfirmNickname">确定</button>
       </view>
     </view>