When RB was updated to use the new avatar services API, this was

mistakenly updated to look up the avatar service. However, the

clean_avatar_service method does this already, so we are attempting to

lookup an item with its ID equal to the class, which isn't going to

work. This would always fail, so submitting the form would unset the

default avatar service. Reverting this fixes the issue,

Able to save the avatar services admin form and the default service gets

changed correctly.