Update ferm-tun.conf.j2

gre/files/ferm-tun.conf.j2

@@ -3,7 +3,7 @@ domain (ip ip6) {
     chain INPUT {
       proto gre saddr (
 {% for name, interface in pillar.ifaces.items() if 'mode' in interface %}
-{%- if interface.mode == 'gretun' -%}
+{%- if interface.mode == 'gretun' or interface.mode == 'gretun6' -%}
         {{ interface.remote }}{{ ' ' }}
 {%- endif %}
 {%- endfor %}