rshd, rlogind: use sockaddr_in for non-native IPv6 clients
    
    In case rshd or rlogind are handed IPv6 socket and connected
    client doesn't support IPv6 natively and it is presented as IPv4
    mapped IPv6, we will detect that and convert structure representing
    connected client to the form which is used for IPv4 clients.
    
    Signed-off-by: Michal Sekletar <msekleta@redhat.com>