pkg/util: Add comment regarding glibc image for check-dns container (#1922)
pkg/util: Add comment regarding glibc image for check-dns container (#1922)

* pkg/util: Add comment regarding glibc image for check-dns container

* pkg/util: Reference more relevant issue for check-dns image comment

hongchaodeng/etcd-operator,coreos/etcd-operator,hongchaodeng/etcd-operator,coreos/etcd-operator