CLOUDSTACK-6790: Disable PXE ROM for system vm nics
FIXED CLOUDSTACK-6781 [Automation] integration.smoke.test_portable_publicip.TestPortablePublicIPRange.test_createPortablePublicIPRange failing on 4.4

Signed-off-by: Abhinandan Prateek <aprateek@apache.org>
Revert "CLOUDSTACK-6781: Disabling failing test corresponding to this bug"

This reverts commit 7bc7377a175260f1efcd79bb77ad64bc9bb93d26.