Machines in discovery have hostname of "fdi"

Support
#1

Problem:
we recently upgraded our discovery image from version 3.1.1 to 3.4.4. Since this machines’ hostnames are set to “fdi” instead of their mac address.
We set the discoverd>Hostname facts setting to discovery_bootif fact

Expected outcome:
machines’ hostnames are their mac address

Foreman and Proxy versions:
1.14.3

Foreman and Proxy plugin versions:
discovery-plugin 8.0.1