[krbdev.mit.edu #1251] krb_save_credentials incorrectly stores interealm tix w/CCAPI

[Alexandra Ellwood via RT]

The krb_save_credentials from KfM's krb4 incorrectly used the ccache
principal's realm as the ticket realm when storing tickets.  It should
be using the realm passed in by the caller.  

As a result, krb4 inter-realm support has been broken in KfM since 1999.

The reason I'm filing this for krb5 is so that this bug doesn't
accidentally get merged into the krb5 support for krb4.