(ge.app:stop) doesn't close window

[kchanqvq]

Hi, I'm on SLY + SBCL 2.0.11 + macOS 10.14.6.
When I call (ge.app:stop), the app window is left open and unresponsive.

[borodust]

Related issue: borodust/trivial-gamekit#44

[borodust]

I don't have MacOS-driven device at hand. This might take a while to fix :)