fix：公告按发布时间排序

cooleshow-cms/src/main/resources/config/mybatis/HelpCenterContentMapper.xml

@@ -73,7 +73,7 @@
 		left join help_center_catalog catalog on content.catalog_id_=catalog.id_
 		left join sys_user su on content.update_by_ = su.id_
 		<include refid="queryConditionUnion" />
-		order by content.order_ asc,content.id_ desc
+		order by content.order_ asc,content.release_time_ desc,content.id_ desc
 		<include refid="global.limit" />
 	</select>