Add Guerillia Group: RPG,backpack,grenades variables in preset

[tiwaz1994]

Suggestion/Feature request

Is your feature request related to a problem? Please describe:

Guerillia groups spawn with predefined RPG, backpack and grenades. Especially annoying for those making WW2 or other historic missions and having resistance units with RPG's show up.

Describe the solution you'd like:

Add variables to the resistance preset to easily change what backpack, AT weapon and grenade they spawn with.