ansible-roles/apache#6 Define default value for Apache version

templates/etc-apache2-sites-available-sd-agent

@@ -12,7 +12,7 @@
 
   SetEnvIf X-Forwarded-For "^.*\..*\..*\..*" forwarded
   LogLevel warn
-{% if apache_version == '2.4' %}
+{% if apache_version|default('2.4') == '2.4' %}
   ErrorLogFormat "[%{u}t] [%l] [pid %P] [client\ %{X-Forwarded-For}i] %M% ,\ referer:\ %{Referer}i"
 {% endif %}
   LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" proxy