Ability to disable keystone revocation polling when using UUID keystone provider
When using a UUID keystone provider revocation is handled by deleting the token from the persistence backend (ie. no revocation lists). If rgw is using keystone authentication rgw_keystone_revocation_interval can be set to an arbitrary period, but it does not seem to have a means of disabling revocation entirely. Ideally there should be another tunable, or rgw_keystone_revocation_interval should allow being set to 0 or -1 to disable revocation polling.