bugfix: 修改未上传图片的用户信息时，上一个操作的图片缓存未清空导致的幻读问题

ruoyi-ui/src/views/system/user/index.vue

@@ -682,6 +682,7 @@ export default {
     handleUpdate(row) {
       this.reset();
       this.photoUrl = null;
+      this.signUrl = null;
       const userId = row.userId || this.ids;
       getUser(userId).then(response => {
         this.form = response.data;