Ticket 49054 - Fix sasl_map unused paramater compiler warnings.
    
    Bug Description:  sasl_map reports unused parameter warnings, but because it's
    a call back the parameters are needed.
    
    Fix Description:  Add the gcc attributes to mask the warnings.
    
    https://fedorahosted.org/389/ticket/49054
    
    Author: wibrown
    
    Review by: mreynolds (Thanks)