engine: import need to set single qxl for windows

Single QXL PCI is now true by default for vmBase, which mean that when
importing VMs/Templates that didn't set this flag get true value for
this entry.
This is not supported for non Linux Os and need to set to false.

Change-Id: I2e62abdf3d484c013adc8dc68a86bfd511737add
Bug-Url: https://bugzilla.redhat.com/1007784
Signed-off-by: Shahar Havivi <shavivi@redhat.com>