Update postfix cookbook

cookbooks/postfix/templates/main.cf.erb

@@ -0,0 +1,14 @@
+###
+# Auto-generated by Chef.
+# Local modifications will be overwritten.
+# Configured as <%= node['postfix']['mail_type'] %>
+###
+
+<% @settings.sort.map do |key, value| -%>
+<%  next if value.nil? -%>
+<%  if value.kind_of? Array -%>
+<%=   "#{key} = #{value.join(', ')}"%>
+<%  else -%>
+<%=   "#{key} = #{value}"%>
+<%  end -%>
+<% end -%>