Dont' require an action-order config section, v1.

If the action-order configuration section is missing, Suricata should just use the defaults instead of exiting with an error.

Optionally we could comment out this section to show that its not required if you want the defaults.

Buildbot output:
- PR build: https://buildbot.openinfosecfoundation.org/builders/jasonish/builds/4
- PR pcaps: https://buildbot.openinfosecfoundation.org/builders/jasonish-pcap/builds/4

I think it may be good here to state where they are set.