datetime: Show timezone properly when it not in expected list
Created by: SunilMohanAdapa
This is important in case we set a timezone (such as 'Etc/UTC') from the old list before move to timedatectl. The value is still okay and is accepted by timedatectl. The first time zone in the list is being shown as the current timezone. This patch fixes the problem.
@JoKeyser , feel free to review this patch (on your way to becoming a reviewer for others :) ).