Revert "engine: import need to set single qxl for windows"

This reverts commit 78c135488743c6eb4f1f57fdf806a8b28b2fc09a.
The OvfManagerTest unit tests was failing due to this change

Change-Id: If88fc448ad87c4c9063c4c1fba6b40e5abf1b99c
Signed-off-by: Tal Nisan <tnisan@redhat.com>