Remove explicit 'none' opt from autounlock handler

Remove explicit 'none' opt from autounlock handler

The autounlock handler included an explicit 'none' option, a choice that
gave it a different UX from similar existing compound option handlers
(e.g. paranoid_confirm or pickup_types), which set 'none' simply by
deselecting all options.  It didn't make the menu any easier to use (at
least in my experience), since in order to go from some combination of
options to 'none', you'd have to deselect everything anyway (which on
its own was enough to set 'none', so there was no reason to explicitly
select it after doing so).

Make the autounlock handler work like other compound option handlers,
such that deselecting all options is the way to set 'none', and there is
no explicit 'none' option included in the list.