The default configuration was changed to use the advanced cache pool in
keystonemiddleware 9.3.0 (Xena release) [1].
This reverts commit 5a52d8e4a0c5d4c246deb8851ef893df63ee0847 (except the
release note).
[1] https://review.opendev.org/c/openstack/keystonemiddleware/+/773939
Change-Id: I290d0a81c57c189b6eb62fc3eee3ed19f441671b