dns_mode defaults to coredns (#3882)
dns_mode defaults to coredns (#3882)

since bad886ca9b86f65e6de31eac18d775a03594518b, dns_mode is set to coredns by default instead of kubedns
kubernetes-incubator/kubespray,kubernetes-sigs/kubespray,kubespray/kargo,kubernetes-sigs/kubespray,kubernetes-incubator/kargo,kubernetes-incubator/kargo,Atoms/kubespray,Atoms/kubespray,kubernetes-incubator/kubespray,kubernetes-sigs/kubespray,Atoms/kubespray,kubernetes-sigs/kubespray,Atoms/kubespray,kubespray/kargo