Fix jcloudsByon: don’t do machine.setParent(null)
- previously the FixedListMachineProvisioningLocation only took
machines that did not already have a parent.
- that meant jcloudsByon needed to “unparent” the rebound jclouds
machine, so it could be added to the FLMPL.
- however, setting parent to null “unmanaged” the location, which
causes problems when it then becomes managed again.