Describe the bug
The error message is not user-friendly when adding duplicate permissions.

Expected behavior
I expect a friendly error message, such as 'This permission already exists, please do not add it again.'

Actually behavior
The prompt is not friendly enough, as it prints out backend stack trace information.

How to Reproduce
Steps to reproduce the behavior:

1. Enter the permission management page.
2. Add a permission.
3. Add the same permission again.
4. See errors

Desktop (please complete the following information):

• OS: [Windows]
• Version [nacos-server 2.4.1]
• Module [config]
• SDK [spring-cloud-alibaba-nacos]

Additional context