Update registry.opensource.zalan.do/teapot/kube-ingress-aws-controller Docker tag to v0.11.21
Update registry.opensource.zalan.do/teapot/kube-ingress-aws-controller Docker tag to v0.11.21

zalando-incubator/kubernetes-on-aws,zalando-incubator/kubernetes-on-aws,zalando-incubator/kubernetes-on-aws