[1.1.74] Can't create new world after creating test world

[Xorimuth]

To reproduce:

- Control click on "Single player"
- Test world is created immediately
- Exit test world
- Normal click on "Single player", "New game", "Next", "Play"
- Expected: Normal world is created
- Actual: Test world is created

Restarting the game resets this.

[Rseding91]

Holding control sets the map size to 50x50, going back to the main menu doesn't reset that. Go into the map settings on the new-game screen and remove the size limit if you no longer want it.