Ticket 48267 - Add config setting to MO plugin to add objectclass
    
    Description:  Add setting to plugin to auto add a predefined
                  objectclass that allows "memberOf" attribute
    
    https://fedorahosted.org/389/ticket/48267
    
    Reviewed by: nhosoi(Thanks!)
    
    (cherry picked from commit b2fe2aab7548a91beb0907071ae66d4e46f2095f)