add test if shorewall is running
"shorewall status" should be enogh:
$ shorewall status Shorewall-4.5.5.3 Status at urchin - Mon Jan 6 16:00:00 UTC 2014 Shorewall is running State:Started (Mon Dec 23 13:26:37 UTC 2013) from /etc/shorewall/
(from redmine: created on 2014-01-06, relates #4806 (closed))