Ticket 413 - "Server is unwilling to perform" when running ldapmodify on nsds5ReplicaStripAttrs
    
    Bug Description:  trying to set nsds5ReplicaStripAttrs yields an error 53
    
    Fix Description:  Needed to check for this new attribute when in the agmtlist modify
                      callback.  When it doesn't recognize the attribute it returns error 53.
    
    https://fedorahosted.org/389/ticket/413
    
    Reviewed by: Richm(Thanks!)
    (cherry picked from commit e86013506df7f3da280d67be2b3bd9ab24b241bf)