ColorKeyColor does not work

[ollipekka]

Version:
Monogame.SpriteBox 1.0.2
Monogame.SpriteBox.PipelineExtension 1.0.3
MonoGame.Framework: 3.7.189
Pipeline: 3.7.189

It looks like there is a problem passing down ColorKeyColor to the actual TextureProcessor.

This is easily reproed:

1. Create a spritesheet with a sprite with no transparency and color 255, 0, 255, 255 (Aqua) as half of the pixels and 0, 0, 0, 255 (black) as half of the pixels.
2. Configure the spritesheet ColorKeyColor to be black and run the pipeline tool
3. Observe how Aqua is actually transparent instead of black.