Request for map update: Zone control

[Jip]

The two Zone Control maps were broken. See also:
- https://github.com/FAForever/fa/issues/3120

This request fixes the crash and also removes one piece of unintended behavior. See also:
- https://gitlab.com/w.b.wijnia/zone-control-maps

And for the changes:
- https://gitlab.com/w.b.wijnia/zone-cont ... 6c3e7ea656

The fix for the crash is removing an import that wasn't in use in the entire script.

The 'unintended behavior' is that the spawned launchers are invulnerable (cannot die / cannot take damage), but can be targeted automatically. In turn, the Fatboy uses about 50% of its guns to target some nearby launcher. I've made them untargetable, matching the other buildings in the base and matching the fact that it is invulnerable.

Given that it is not my map I cannot upload these changes myself. What is the approach that I can take to make the maps work again? The working versions can be downloaded from the Gitlab repository.