refactor(Example): 修复 wx:key 语法错误的问题

Author: juzi214032

examples/pages/navigator/filter/index.wxml

@@ -6,7 +6,7 @@
       <detail-navi-card
         wx:for="{{baseNaviConfigs}}"
         wx:for-item="baseNaviConfigs"
-        wx:key="{{index}}"
+        wx:key="index"
         icon="{{baseNaviConfigs.icon}}"
         title="{{baseNaviConfigs.title}}"
         componentsPath="{{baseNaviConfigs.componentsPath}}"