Use config storage for client OTP token selection

* Save the vendor name of the token we used to create the challenge.
* If we saved the name of a token vendor previously, prune out any
  tokeninfos which contain different vendor names.

(cherry picked from commit 4c1e02bef34df0407323b610818980c25b61c878)

https://github.com/krb5/krb5/commit/2d5d2532627144688768cea34be8a43cc397901a
Author: Nalin Dahyabhai <nalin@redhat.com>
Committer: Tom Yu <tlyu@mit.edu>
Commit: 2d5d2532627144688768cea34be8a43cc397901a
Branch: krb5-1.11
 src/lib/krb5/krb/preauth_otp.c |   90 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 90 insertions(+), 0 deletions(-)