Ticket 47968 - Change to slapi_UTF8NCASECMP
    
    Bug Description:  > ldap/servers/slapd/log.c:420:51: warning: pointer targets in
    passing argument 2 of 'slapi_utf8ncasecmp' differ in signedness [-Wpointer-sign]
    
    Fix Description:  We should change to use slapi_UTF8NCASECMP
    
    Commit under "1 line" rule.
    
    https://fedorahosted.org/389/ticket/47968
    
    Author: wibrown
    
    Review by: nhosoi (Thanks)