bind: don't use public-ns for internal reverse zones

salt-pillar/bind/dns.sls

@@ -4,7 +4,7 @@ bind:
   public-ns:
     - ns.c3d2.de
     - spaceboyz.net
-  serial: 2017011300
+  serial: 2017012300
   
   reverse-zones-inet:
     - 72.20.172.in-addr.arpa

salt/bind/reverse.zone

@@ -8,9 +8,7 @@ $TTL 10M
 				2H ; expire
 				5M ; minimum
 			)
-{%- for ns in pillar['bind']['public-ns'] %}
-		IN NS	{{ ns }}.
-{%- endfor %}
+		IN NS	{{ pillar['bind']['master-ns'] }}.
 
 {%- for net, hosts in pillar['hosts-inet'].items() %}
 {%-   for host, aaaa in hosts.items() %}