---
upgrade:
  - |
    PKI token support has been dropped from horizon. PKI token was removed
    from keystone in Ocata release which was released two years ago.
    It is a good timing to drop its support.

    ``OPENSTACK_TOKEN_HASH_ALGORITHM`` setting was removed because it was
    used only for PKI token check. Unless you use PKI token before upgrading,
    there is no affect and you can safely drop it from your local_settings.py.