Adjust check for semi_major_spawning_radius
The semi_major_spawning_radius is used for despawning too, which cann't be zero. Therefore this condition is changed so that the Error message is not misleading.
Edited by Andreas Rauschert
The semi_major_spawning_radius is used for despawning too, which cann't be zero. Therefore this condition is changed so that the Error message is not misleading.