Fix OTP tests with pyrad 2.x

Declare User-Password as having type "octets" instead of "string" or
pyrad 2.x will throw a decoding error when retrieving it.

(cherry picked from commit 57dc24093015d292189ef23313ef8ff2a81431e4)

https://github.com/krb5/krb5/commit/0b65438bbe5906a857f95e5a5dd4739021d4b57b
Author: Greg Hudson <ghudson@mit.edu>
Committer: Tom Yu <tlyu@mit.edu>
Commit: 0b65438bbe5906a857f95e5a5dd4739021d4b57b
Branch: krb5-1.13
 src/tests/t_otp.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)