Fix for rack 2.0.8

[le0pard]

No description provided.

[madmatvey]

Need integration tests.

[le0pard]

@madmatvey I cannot write tests, because this changes depend from redis-rack and I cannot point to branch in gemfile spec (need point to new redis-rack version with fixes)

[tubbo]

@le0pard these tests passed when I ran bundle update locally. now that your PR is merged to redis-rack, you should be able to test against the new API by adding this to Gemfile:

gem 'redis-rack', github: 'redis-store/redis-rack'

[le0pard]

@tubbo Big thanks. I added redis-rack from github for testing purpose, but you need to remove it after release new redis-rack version :)