Previous to this change, the GSS code avoids caching S4U2Proxy results
for fear of the memory cache growing without bound, but that seems
unlikely to be a serious problem.  Allow these to be cached.

https://github.com/krb5/krb5/commit/f388eb9673062d8e4eb7d359be2dcaff2acba768
Commit By: ghudson
Revision: 25530
Changed Files:
U   trunk/src/lib/gssapi/krb5/init_sec_context.c