Fix a link -- there is no starship.python.org!

Doc/doc/doc.tex

@@ -224,7 +224,7 @@ distribution, to create or maintain whole documents or sections.
   fairly cohesive module libraries.  Examples of the later use include
   the standard \citetitle[../mac/mac.html]{Macintosh Library Modules}
   and
-\citetitle[http://starship.python.org/crew/fdrake/manuals/krb5py/krb5py.html]{Using
+\citetitle[http://starship.python.net/crew/fdrake/manuals/krb5py/krb5py.html]{Using
   Kerberos from Python}, which contains reference material for an
   extension package.  These documents are roughly equivalent to a
   single chapter from a larger work.