Fixes M2010 spawns re: modpack.

These definitely don't fit in the 'oldies' pack, and they're already set
to spawn uncommonly in the vanilla game. Coupled with the ammo fix PR
#7931 this should fix the errors in spawning winmag ammo.
Merge pull request #7932 from Rivet-the-Zombie/spawn-swap

Fixes M2010 spawns re: modpack.