Bump node local dns version to 1.15.11 (#5805)

k8s-dns-node-cache now uses debian-iptables base images
to automatically use either iptables-legacy or iptables-nft
https://github.com/kubernetes/dns/pull/355
https://github.com/kubernetes/kubernetes/pull/82966



This adds support CentOS 8

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>