[CLIENT] Lock on OSX Sierra

1. Finish pick phase.
2. During countdown, open a .dmg file that is encrypted.
3. Leave the password box open until the LoL game tries to start.
4. Witness black screen.

For some reason, the game was unable to start while the password box was up. But I couldn't alt-tab out or force quit either, because the OS was giving focus to the password box while the LoL screen was overlaying it.