Description of problem:
When you try to edit/create a new interface on the host and enter an invalid MAC address and then submit the changes there will be an error message shown
"'fa:16:3e:17:3e:19x' is not a valid MAC address and is not a valid MAC address".

"is not valid MAC address" is there twice and should be just once.

Version-Release number of selected component (if applicable):
satellite-6.13.0-6.el8sat.noarch
foreman-3.5.1.14-1.el8sat.noarch
Red Hat Enterprise Linux release 8.7 (Ootpa)

How reproducible:
Every time

Steps to Reproduce:
1. Go to any host
2. Try to edit the MAC address in any interface to some wrong value
3. Submit changes
4. See the error message

Actual results:
Invalid MAC address message appears twice while editing the interface.

Expected results:
Invalid MAC address message should appear just once while editing the interface.