Release v19.33.4

Fixed

• A rejected reactor or reducer registration no longer breaks later calls on the same connection. Before, a keep-alive or another call sent while the failed stream was closing could fail with "Reading is already in progress". (#4537)
• A rejected reactor or reducer registration now ends the call with an error that the client sees. Before, the call could end as successful while the client kept waiting. (#4537)
• A reactor or reducer registration with a missing event type is rejected with a clear error instead of failing inside the kernel. (#4537)