FreeIPA: sync looks at all users in CF not just active users

[dsajdak]

When running the FreeIPA sync tool it currently looks at every user in the ColdFront database and compares it to FreeIPA. This can take a very long time to run with large user base and may affect FreeIPA performance. Would be good if there was a way to avoid this - if a ColdFront user is inactive, don't check FreeIPA? This may also tie into this: https://github.com/ubccr/coldfront/issues/173