### _Why are the changes needed?_
Fix broken link in `kerberos.rst`
### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible
- [x] Add screenshots for manual tests if appropriate
- [ ] [Run test](https://kyuubi.readthedocs.io/en/master/develop_tools/testing.html#running-tests) locally before make a pull request
Closes#4361 from Yikf/kerberos-doc.
Closes#4361
26145902 [Yikf] fix break link
Authored-by: Yikf <yikaifei@apache.org>
Signed-off-by: Yikf <yikaifei@apache.org>