icinga2x-graylog2: Ensure httpd runs after a reboot.
icinga2x-graylog2: Create and use define for firewall rules.
icinga2x-graylog2: Make sure selinux setting is persistet.

Unbreaks Icinga2 web interface after a reboot without running puppet.
icinga2x-graylog2: Restart icinga2 if any file in conf.d/ changes.
icinga2x-graylog2: Fix Graylog2 server urls.