Update IPA userclass param when an existing host is assigned a new realm
The smart-proxy should be triggered to update the 'userclass' parameter in IPA if a user selects a new realm on a host that already exists in Foreman. Current functionality only updates the userclass parameter if the host-group changes.
The use case for this issue is applying a new realm to a host that already exists in Foreman that a) doesn't have a realm configured at all or b) needs a new realm to be configured. The 'userclass' param in IPA should be updated when this occurs, so any new automember rules can be processed to reflect the changes in Foreman.