Update Camellia feature description

Remove the potentially misleading "experimental" annotation on the
description of the Camellia encryption feature.  Also update the I-D
version to match the IESG-approved version.

https://github.com/krb5/krb5/commit/4810efbbf2671b08ffbbf7dc8a94aa9d52d43cca
Author: Tom Yu <tlyu@mit.edu>
Commit: 4810efbbf2671b08ffbbf7dc8a94aa9d52d43cca
Branch: master
 doc/mitK5features.rst |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)