password change for former SAML user not working

### problem

As an admin I'm able to reset password for a regular user without problems.
If SAML has been enabled for that user this is no longer possible within CloudStack. Expected behavior.
Once I disable SAML for that user I would expect that I'm able to change the password again. That is not the case and the error below will appear.

### versions

ACS 4.20.1

### The steps to reproduce the bug

1. run all steps as admin
2. create a user
3. reset the password for that user
4. enable SAML (needs to be configured before) for this user
5. try to reset the password (will fail)
6. disable SAML for this user
7. try to reset the password (should work?) will fail
...

### What to do about it?

Enable the possibility to change the password for a former SAML user.

在 CloudStack 4.20.1 中重現管理員密碼重設流程：建立使用者、啟用 SAML、停用 SAML，然後重新嘗試重設。追蹤密碼變更進入點和使用者的 SAML 狀態；當管理員在停用 SAML 後可以重設密碼且不再出現所回報的錯誤時，即表示完成。

由索引模型根據 Issue 內容生成。