[GREENFOOT-793] World not automatically instantiated in new scenario
This used to happen in 3.1.0 but does not happen in 3.5.0. I believe the reason for the change is that the logic used to be "If only one world, instantiate automatically", but we removed that as it isn't necessarily what is wanted. But we should cover the new scenario case, probably most easily by setting the lastWorld property in the project file when making a new scenario.
- Issue type: Bug
- Priority: Medium
- Fix versions: 3.5.1