Handle connection failure in the case of invalidation
Reorganized the previous solution a bit, changed the name of the setting
Handle also a connection failure on schemes loading
Treat the simple cache utilization (trying to get from cache) as a cache miss if we cannot connect
Short-circuited the logic in `ensure_known` in case we fail to load schemes
Decorate also `cache_thing`
Refactored SafeRedis a bit to reuse the handle_connection_failure decorator