add missing krb5_free_keytab_entry_contents()
add missing krb5_free_keytab_entry_contents()

noticed by bland@bbnest.net
Fixes #288

git-svn-id: 1c032ccab86ccfbd91a527b68be6efa4b7c92a66@3005 e27351fd-9f3e-4f54-a53b-843176b1656c

RavuAlHemio/python-kerberos,RavuAlHemio/python-kerberos,RavuAlHemio/python-kerberos