fix 'assets' dir not found exception;

fix add user fail issue

README.md

@@ -1,5 +1,7 @@
 # frps-multiuser
 
+[README](README.md) | [中文文档](README_zh.md)
+
 frp server plugin to support multiple users for [frp](https://github.com/fatedier/frp).
 
 frps-multiuser will run as one single process and accept HTTP requests from frps.
@@ -23,8 +25,6 @@ frps-multiuser will run as one single process and accept HTTP requests from frps
 ***when a user is dynamic been `remove` or `disable`,it will take some time to be effective***
 ***the limit of `ports`、`domains`、`subdomains` only effective at `NewProxy`***
 
-[README](README.md) | [中文文档](README_zh.md)
-
 ### Features
 
 * Support multiple user authentication by tokens saved in file.
@@ -132,6 +132,8 @@ remote_port = 6000
 
 ## Issues & Ideas
 
+___If you want visit mange ui from internet, you should change `plugin_addr` to `0.0.0.0`___
+
 If you have any issues or ideas, put it on [issues](https://github.com/yhl452493373/frps-multiuser/issues). I will try my best to achieve it.
 
 ## Credits