typedef void (*SilcSFTPErrorCallback)(SilcSFTP sftp,
                                          SilcSFTPStatus status,
                                          void *context);

    Error callback is called if a connection error occurs during SFTP
    session.  If the connection or stream is closed this callback is
    called.  Other errors are delivered in other callbacks.  Only the
    SILC_SFTP_STATUS_EOF or SILC_SFTP_STATUS_NO_CONNECTION is delivered
    in this callback.