chore: dropdown snap

Author: Amour1688

components/dropdown/__tests__/__snapshots__/dropdown-button.test.js.snap

@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`DropdownButton should support href like Button 1`] = `
-<div class="ant-btn-group ant-dropdown-button"><a href="https://ant.design" class="ant-btn ant-btn-default">
+<div class="ant-btn-group ant-dropdown-button"><a class="ant-btn ant-btn-default" href="https://ant.design">
     <!---->
   </a>
   <!----><button class="ant-dropdown-trigger ant-btn ant-btn-default" type="button">