configure.in patch for krb support

[David W. Chapman Jr.]

> Finally, you are missing one patch however:  You need to change the
> version number to add some FreeBSD identifier.  We had a nasty thing
> where the debian people 'fixed' a bug, and we didn't notice till our
> users complained that the fix was rather broken.  The user's didn't even
> know they were running a modified package.
>
Where exactly would I add this.  Excuse my ignorance, but I don't do much
programming, I just maintain the samba ports on FreeBSD.