Remove redundant copy operation in pxe_enabled update code
Remove redundant copy operation in pxe_enabled update code

I cannot remember why I added it, I assume it's not needed.
This is a follow-up to 782ee92c45f2875af62aaf913f550e9e6bde7dc8.

Change-Id: Iaa892e072db87fbcff0804cecd932670edf823df

openstack/ironic-inspector,openstack/ironic-inspector