Fix checks for presence of old-style 'enabled' key

'iptables:service:enabled' is a key from old version of 'iptables'
formula. New formula relies on the fact that old-style pillar data
is not present.

Testing if 'pillar.iptables.service.enabled' is / is not defined
will fail is 'pillar.iptables.service' is not defined.

This commit fixes the issue by using 'service' data structure
retrieved with defaults values of empty dicts.

Change-Id: I820ead66f6067dd66c9e19f7b748455d8752924c
diff --git a/iptables/init.sls b/iptables/init.sls
index 9690eff..87c46ee 100644
--- a/iptables/init.sls
+++ b/iptables/init.sls
@@ -8,8 +8,9 @@
   - name: echo "You are trying to use iptables inside of docker or lxc. Kernel modules loading are not supported here"
 {%- endif %}
 
-{%- if pillar.iptables.service.enabled is defined %}
-{%- set include_allowed = false %}
+{%- set service = pillar.get('iptables', {}).get('service', {}) %}
+{%- if service.enabled is defined %}
+  {%- set include_allowed = false %}
 echo_usupported_pillars_schema:
   cmd.run:
   - name: echo "You are trying to use old style pillars schema. Please update pillars according to the current schema"
diff --git a/iptables/v1/init.sls b/iptables/v1/init.sls
index 224d268..b67ca31 100644
--- a/iptables/v1/init.sls
+++ b/iptables/v1/init.sls
@@ -1,5 +1,6 @@
 {%- from "iptables/map.jinja" import schema with context %}
-{%- if pillar.iptables.service.enabled is not defined %}
+{%- set service = pillar.get('iptables', {}).get('service', {}) %}
+{%- if service.enabled is not defined %}
 include:
   - iptables.v{{ schema.epoch }}.v4_service
   - iptables.v{{ schema.epoch }}.v6_service