Fix held item overlay UIScale calculation.
Fix held item overlay UIScale calculation.

Now correctly bases UI scale off viewport control and doesn't break if scale is automatic.

space-wizards/space-station-14,space-wizards/space-station-14,space-wizards/space-station-14,space-wizards/space-station-14,space-wizards/space-station-14,space-wizards/space-station-14