Ticket 47532 - 1.3.1 with mozldap crashes in new operation work_q code
    
    Bug Description:  The changes from ticket 513 seem to trigger two crashes when using mozldap.
    
    Fix Description:  When freeing a operation/ber we need to check if the ber is NULL, and
                      when getting a operation from the stack and stack operation is NULL,
                      we need to create a new operaton, and not try to init the empty one.
    
    https://fedorahosted.org/389/ticket/47532
    
    Reviewed by: rmeggins(Thanks!)