Add RackAttack info to structured logs

https://docs.gitlab.com/ee/security/rack_attack.html#remove-blocked-ips-from-rack-attack-via-redis

rack attack logs are currently going to production.log, it would be helpful to SREs to have these log messages in structured logging, production_json.log. This would allow us to do queries using the existing logging infrastructure in kibana, instead of using the the unstructured production.log which lacks timestamps and other helpful information.

Follow ups:

Edited by Mayra Cabrera