Update README_zh_CN.md

Author: skiffer-git

README_zh_CN.md

@@ -1,16 +1,5 @@
 # openim-chat
 
-## 📄 开源许可证 license
-
-This software is licensed under a dual-license model:
-
-- The GNU Affero General Public License (AGPL), Version 3 or later; **OR**
-- Commercial license terms from OpenIMSDK.
-
-If you wish to use this software under commercial terms, please contact us at: contact@openim.io
-
-For more information, see: https://www.openim.io/zh/licensing
-
 
 
 ## 🧩 功能简介