Just some minor extensions when we delete system users.
Before we delete a user account - we kill it's session and force a log-out. In theory the user could log back in in a very tiny window and prevent the deletion of the account.
To prevent this loophole the account should be disabled before we force a logout.
Source code: https://github.com/vyos/vyos-1x/blob/175b0a082808955adba811f18424a126e798dd32/src/conf_mode/system-login.py#L253-L259
When we clean the user, we should also force it's file removal