https://fedorahosted.org/389/ticket/443
https://fedorahosted.org/389/attachment/ticket/443/0001-Trac-Ticket-443-D...
Bug Description: Even if setting a config parameter to nsslapd-
allowed-to-delete-attrs, the value failed to delete if the type
was on|off or integer.
Fix Description: Store all the initial config param values in
ConfigList. If the attribute value is deleted, reset the initial
value.