LDAP startsWith eduPersonAffiliation invalid config

When choosing the "eduPersonAffiliation" startsWith configuration, it asks for the group attribute to provision for the membership (default was extension). This value used to be entered in the "Group attribute name for memberships" field. In 2.6.19, the drop down for that field only has the 4 group cache buckets, and the group attributes no longer show up. This makes the field have a blank value, and can't save since it's a required field.

Note that the field description still reads "The group attribute that has values...", even though group attributes are no longer options