[MINOR] Making the attenuation goggles suck a whole lot less with a simple change

[Sundance]

Have HUD toggle to turn it on/off; the latter being normal sight.
This stops people from having to physically take them off, occupying a hand-slot for an item that has a very minor advantage.
(please don't derail this into 101 idea's of the usefulness on the goggles, there was already a long discussion about that. This minor change would signifcantly improve them, while still staying true to the source)