Unset bad background image.

[Geneticus]

There does not seem to be a way to remove a problematic background image other than providing a bogus filename. It is also possible to use an image that completely conflicts Visual Studio 2017 and makes it difficult to navigate back to the settings once applied. Should have a countdown to auto-reverse change if not accepted.

[hishaks]

I had to unset the image using a completely transparent png image. There should be a way to reset changes, unset background image.