Bug: FinalLightFace uses all threads available, ignoring -threads

[Laveig]

Describe the bug

When -threads is specified in vrad launch parameters, every compilation process uses the exact number of threads specified after -threads, except for FinalLightFace - it uses all threads avaliable, completely ignoring the parameter.

This makes it very annoying to use a PC when compiling a map in the background, I tell the compiler to use this amount of my PC and it straight up uses more.

To Reproduce

1. Add -threads 1 to $light_exe parameters
2. Compile any (heavy) map
3. Random lag spike go

Issue Map

Any

Expected Behavior

FinalLightFace uses the exact amount of threads as defined after -threads

Operating System

Any