Fix Unit::_cleanUp() so "app/resources/tmp/tests/empty" file is not deleted on Windows.
Fix Unit::_cleanUp() so "app/resources/tmp/tests/empty" file is not deleted on Windows.

Signed-off-by: David Persson <cd3b5183a9c400336ad0c67323c823ddfec74be5@gmx.de>

wbeater/lithium,SensCritique/lithium,UnionOfRAD/lithium,graphis/lithium,UnionOfRAD/lithium,pixelcog/lithium,jails/lithium,davidpersson/lithium,m4rcsch/lithium-core-library,pixelcog/lithium,whowgames/lithium,wbeater/lithium,qoqa/lithium,muyehub/lithium,graphis/lithium,datachand/lithium,m4rcsch/lithium-core-library,davidpersson/lithium,qoqa/lithium,datachand/lithium,SensCritique/lithium,jails/lithium,muyehub/lithium,mehlah/lithium,mehlah/lithium,whowgames/lithium