Prevents the aero tinting from blocking other mods

With the current system, in LateUpdate the part glow will always be set even if only to default. This prevents other mods (like DangIt, or TAC Fuel Balancer) from using the highlight function.

With this edit, now the code keeps track if the tinting has been activated. If the user hasn't selected any tinting, it will be reset to default only once, letting other mods control it when you are not using it.