Add PKINIT test case for generic client cert

In t_pkinit.py, add a test case where a client cert with no extensions
is authorized via subject and issuer using a pkinit_cert_match string
attribute.

https://github.com/krb5/krb5/commit/8c5d50888aab554239fd51306e79c5213833c898
Author: Greg Hudson <ghudson@mit.edu>
Commit: 8c5d50888aab554239fd51306e79c5213833c898
Branch: master
 src/tests/t_pkinit.py |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)