v0.9.4 crashes when clicking in empty measures

Hi folks, just letting you know about this small problem.

Basically, if you have an empty measure or extra empty space in a measure with music in it (don't know how I got the space in there) and then click into that empty space, the app (or just the score if there's more than one) immediately crashes. It's a repeatable problem on my PC.

- Create a new score with any settings at all.
- Click on a rest in any measure to select it
- Click on the "rest" button in the toolbar to remove the rest. This appears to create an empty measure.
- Now click on the empty space where the rest was in that measure.
- Crash! At least for me.

I discovered this by accident and narrowed it down while trying to simply delete measures. I know the correct process now, but once measures are empty they cannot be manipulated without crashing the score. I had to edit the MSC file directly and re-add it back to the .MSCZ file to get it working properly.

FWIW, installation went quickly and without problems.

Thanks,
-Tony