Make configuration files more readable

In order to make OpenStack configuration files written by Chef more
readable, this patch introduces a blank line before every section
heading.

Change-Id: Ib44e17cbba512c51c0098177d2dab1a91802b4d3

templates/default/openstack-service.conf.erb

@@ -1,5 +1,6 @@
 <%= node['openstack']['common']['custom_template_banner'] %>
 <% @service_config.each do |section, values| -%>
+
 [<%= section %>]
   <% values.each do |key, value| -%>
   <% if value.class == Hash -%>