Crashes Glyphs App in 1115

[Cracel]

Hello.
Everytime I close the project (on the red button or on File > Close), Glyphs crashes and I think that labelKey might be responsable. I came to this conclusion after disabling all plug-ins and then activating one by one. Glyphs works fine if labelKey isn't installed. I already did a fresh new install of labelKey plugin but the results are the same. Hope it helps ;)
Cheers.

[schriftgestalt]

I send a pull request that fixes this already.