v2-rewrite: Minor warnings

[FinishedFragment]

I tested v2-rewrite a bit and noticed a few minor warnings. These are not gamebreaking and possibly low priority.

The first two always appear when joining a new world. The stamina-related one does not appear in creative mode.

WARNING[Server]: Assignment to undeclared global "aeffect" inside a function at ...Lord-of-the-Test/mods/lottplayer/effects/physics.lua:49.
WARNING[Server]: Assignment to undeclared global "stamina_regen_amt" inside a function at ...Lord-of-the-Test/mods/lottplayer/systems/stamina.lua:122.

When choosing Iron Hills Dwarf as race there will be a warning because of the biome:

WARNING[Emerge-0]: Assignment to undeclared global "j" inside a function at ...Lord-of-the-Test/mods/lottmapgen/technical/functions.lua:1196

This warning might not appear instantly but it will eventually pop up when roaming the biome.