Purge unused layer folders in test start_with_empty_mdel.
Purge unused layer folders in test start_with_empty_mdel.

SketchUp/testup-2,thomthom/testup-2,thomthom/testup-2,SketchUp/testup-2,SketchUp/testup-2,thomthom/testup-2,SketchUp/testup-2,SketchUp/testup-2,thomthom/testup-2,thomthom/testup-2,thomthom/testup-2,SketchUp/testup-2