修复开发模式下，右侧设置按钮不展示的问题

https://github.com/sendya/ant-design-pro-vue/issues/667#issue-576023437

src/components/SettingDrawer/SettingDrawer.vue

@@ -6,7 +6,6 @@
       @close="onClose"
       :closable="false"
       :visible="visible"
-      :handle="handle"
     >
       <div class="setting-drawer-index-content">
 
@@ -161,7 +160,7 @@
           </a-alert>
         </div>
       </div>
-      <div class="setting-drawer-index-handle" @click="toggle">
+      <div class="setting-drawer-index-handle" @click="toggle" slot="handle">
         <a-icon type="setting" v-if="!visible"/>
         <a-icon type="close" v-else/>
       </div>
@@ -185,8 +184,7 @@ export default {
   data () {
     return {
       visible: false,
-      colorList,
-      handle: <div/>
+      colorList
     }
   },
   watch: {