Revise iCloud Private Relay blocked domains

According to both Apple's [official documentation](https://developer.apple.com/icloud/prepare-your-network-for-icloud-private-relay/) and Control D's [official documentation](https://docs.controld.com/docs/icloud-private-relay), it is suggested to add both **mask.icloud.com** and **mask-h2.icloud.com** to the blocklist to block Private Relay access.
