Completely omit noise and smoke from off-map vehs

I'd left the noise in, thinking it should draw hordes, but if the noise is going to be happening inside the reality bubble and confusing players, that's not such a great idea.
I don't think it's because of the change to the parameters of `noise_and_smoke` -- it was never supposed to stop noise from occurring in the first place. I'll dig deeper into this, thanks for letting me know.