!557 修改创建菜单时permission为空，缓存KEY 为空的BUG

Merge pull request !557 from 杜继强/master

yudao-module-system/yudao-module-system-biz/src/main/java/cn/iocoder/yudao/module/system/service/permission/MenuServiceImpl.java

@@ -45,7 +45,7 @@ public class MenuServiceImpl implements MenuService {
     private TenantService tenantService;
 
     @Override
-    @CacheEvict(value = RedisKeyConstants.PERMISSION_MENU_ID_LIST, key = "#reqVO.permission")
+    @CacheEvict(value = RedisKeyConstants.PERMISSION_MENU_ID_LIST, condition = "#reqVO.permission != null",  key = "#reqVO.permission")
     public Long createMenu(MenuCreateReqVO reqVO) {
         // 校验父菜单存在
         validateParentMenu(reqVO.getParentId(), null);