krb5_get_cred_from_kdc_opt returns KRB5_REALM_UNKNOWN instead of KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN

[Sam Hartman]

Your ticket has been updated with references and a pointer to the
problem.

In general, you don't need to notify us about bugs you have opened,
although it did get you a response sooner in this instance.