When ignore_puppet_facts_for_provisioning is false, the MAC address Foreman has registered for a host may be updated if the host wasn't provisioned on Facter's view of the "primary" interface. The DHCP reservation (and TFTP file I suppose) are on the old MAC address, and Foreman doesn't allow the user to edit this back.

Steps to Reproduce:
1. Provision a controller node using the mac address of the eth2 interface.
2. Check the hosts properties in the Foreman dashboard, the MAC address changes to a the MAC of the eth0 interface.
3. Edit the hosts network information.
4. Change the MAC address of the primary interface to the correct MAC address.
5. Attempt to submit the changes. Following error occurs:

in DHCP detected - expected example.redhat.com-00:00:c8:9c:e4:ae/10.1.1.1, found example.redhat.com-00:1a:63:76:00:20/10.1.1.1

6. Choosing Overwrite afterwords fails with same error.