Overlay is black when no images found

[micheldebree]

Found in the linux version; because there are no overlay images for 'linux' platform, they cannot be loaded. The overlay does switch on and goes to black. On macOS it also flickers. I would expect the overlay not to switch on, maybe an error message aswell.

[Chordian]

The overlay images for Linux doesn't exist yet because I need to know the hotkeys used in the Linux version.

[Chordian]

They have since been added, but for now they have the same hotkeys as the Windows version.

[strbm]

Overlay doesn't change after replacing/loading another driver.