use first China DNS as apt-cacher dns

templates/docker-compose.yml.j2

@@ -52,7 +52,7 @@ services:
   apt-cacher-ng:
     restart: always
     build: apt-cacher-ng-docker
-    dns: 114.114.114.114
+    dns: {{ smartdns_china_dns[0] }}
     ports:
 {% if apt_cacher_address %}
 {% for address in apt_cacher_address %}