add fixes to knot-dns

knot-dns/files/nextnode.conf.j2

 {# upstream docu: https://www.knot-dns.cz/docs/latest/html/modules.html?highlight=subnet#using-subnets #}
 
 nextnode.ffffm.net:
-  {{ salt['nextnode.knot_yaml']()|yaml(False)| indent(2) }}
+  {{ salt['nextnode.knot_yaml']()|yaml(True)| indent(2) }}

knot-dns/init.sls

@@ -35,7 +35,7 @@ knot:
       - pkg: git
       - pkg: knot
 
-//var/lib/knot/nextnode.conf:
+/var/lib/knot/nextnode.conf:
   file.managed:
     - source: salt://knot-dns/files/nextnode.conf.j2
     - user: knot