Warning about peg generators when saving pops up multiple times if there are multiple peg generators

[LeeSpork]

When I create a level with multiple peg generators and save my project, the window saying "One or more of your levels contains a peg generator or similar object" opens once for every peg generator, one after another, which is annoying when I have a lot of generators that I'm not ready to apply yet. Ideally, it would only show once per click of the save button.