4.13.2 de-bugging

[stugumby]

This is not a new bug but an annoying long term hold out.
Opel blitz trucks standard color is panzer grey, they do not change color for desert or winter maps, yet the opel ambulance does. The standard cargo truck gets a winter cover on the back but the skin stays panzer grey.The radio truck is always in 3 color scheme.

Russian fuel tanker and standard truck/ radio truck stay russian green on all maps, gaz trucks and ambulance from later add ons change from green to winter.