Bug 611: fix for iponly

Fix Bug 611 for ip-only rules as well. If 'alert ip' rule has ports,
don't match on protocols that don't have ports. Like ICMP.

Bug #611. https://redmine.openinfosecfoundation.org/issues/611

Prscript:
- PR build: https://buildbot.suricata-ids.org/builders/inliniac/builds/220
- PR pcaps: https://buildbot.suricata-ids.org/builders/inliniac-pcap/builds/140