Code review comment for lp:~mterry/ubuntu-system-settings/revoke-auth

In testing I've confirmed it does require the old password in each attempt. However, a couple times in the change password dialog, I ran in to cases where using an incorrect current password silently failed to change the password. It's good that it didn't actually change the password, but the UI didn't show the incorrect password error. I can't reproduce it reliably, not sure if it is a regression or not. I'll do the same test without this branch now.