politeiawww: Password change bug.

[degeri]

There is no check to ensure that the the "current password" and the "new password" are different when changing passwords. Ideally for a clean UX, the user should not be allowed to change the password to itself.

We can do this on the client side too. Not really an major issue.

[lukebp]

We'll address this in the upcoming user layer rewrite that is part of the Pi 2021 Q3 proposal. Marking this as blocked for now.