Fix leak in krb5_server_decrypt_ticket_keytab()

When we skip a keytab entry because it is of the wrong enctype, free
it before continuing.

(cherry picked from commit 9984c2343c96f3aaaf8a8d6dfc1b6de1eae533c2)

https://github.com/krb5/krb5/commit/84381ce2197ae41165ae479a503c51306660dc62
Author: Seemant Choudhary <seemant@soha.io>
Committer: Tom Yu <tlyu@mit.edu>
Commit: 84381ce2197ae41165ae479a503c51306660dc62
Branch: krb5-1.14
 src/lib/krb5/krb/srv_dec_tkt.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)