Compiles and runs fine on Leap 15.0, should not be excluded.

Also I see no difference between this package and gens-opengl (also before my specfile changes). Both versions support OpenGL. The package "gens-opengl" probably can be removed.

@Ulih: review reminder

It does build on Tumbleweed (locally). There currently is a problem with the build service. The error is "Invalid type 'Q' in pack at /.build/computeblocklists line 113"