Thanks for catching that. On EPEL 7 it needs to depend on python-backports, not python2-backports. I'll fix that right up.
Confirmed, this update resolves the firewalld bug. I tested by doing the following:
firewall-cmd --add-service=freeipa-ldap --permanent
firewall-cmd --add-service=freeipa-ldaps --permanent
All went well.
Basic functionality appears to work fine. Additionally, this update resolved a serious issue I was having with the Nouveau driver on my Lenovo P50 laptop. Previously I couldn't select the external monitor as the primary monitor within GNOME because it would result in terrible flickering on that display. This is no longer the case on 4.16.3.