memo CFn SecurityGroupIngress

• GroupNameにGroupIdを入れるとThe security group xxx does not exist in default VPC xxxみたいなエラーが出る
• SGにSGを参照させる場合でも一応 IpProtocol は必要

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-security-group-ingress.html