Apply patch from Arlene Berry to handle the case where a mechanism
implements set_cred_option but does not implement the requested
option.

https://github.com/krb5/krb5/commit/fb17c38c7f85eecc87132484de2bdf4688cb5d33
Commit By: tlyu
Revision: 23698
Changed Files:
U   trunk/src/lib/gssapi/mechglue/g_set_cred_option.c