[krbdev.mit.edu #6788] document preferred_preauth_types

[Tom Yu via RT]

"Sam Hartman via RT" <rt-comment at krbdev.mit.edu> writes:

> In a discussion on krbdev, Nico told Russ that krb5.conf could force
> preauth.
> Russ said he was unaware of that option; Nico thought he must have been
> mistaken.
> However, Quoting get_in_tkt.c:
>
>     ret = krb5int_libdefault_string(context, realm,
>     KRB5_CONF_PREFERRED_PREAUTH\
>     _TYPES,
>                                         &preauth_types);
>                                         
>
>
> This option should be documented.

Do you have suggested text?