Fix default_resolver is undefined

fix issues #2265

roles/dnsmasq/templates/01-kube-dns.conf.j2

@@ -22,7 +22,7 @@ server={{ srv }}
 {% endfor %}
 {% elif resolvconf_mode == 'host_resolvconf' %}
 {# The default resolver is only needed when the hosts resolv.conf was modified by us. If it was not modified, we can rely on dnsmasq to reuse the systems resolv.conf #}
-server={{ default_resolver }}
+server={{ cloud_resolver }}
 {% endif %}
 
 {% if kube_log_level == '4' %}