FR: Flag to remove missile failsafe detonation

Right now missiles have a failsafe detonation range in which they'll detonate near the target in an attempt to deal damage if the engine calcs that they'll miss, 10 meters + 4 'frames' distance away according to Baezon/Asteroth.

A flag to remove this failsafe detonation would be a nice thing to have for both balance and aesthetic purposes, such as in this case where I have a missile without a warhead.