Session and match_ip ignore proxy

Our web setup uses docker containers behind some proxies. What I see when I use match_ip for sessions is the ip address of the proxies.

All I've done is copy the system/libraries/Sessions/drivers/Session_redis_driver.php file to application/libraries/Sessions/drivers/MY_Session_redis_driver.php and just overrode the methods that used $_SERVER['REMOTE_ADDR'].

According to the documentation, this how you override core files.