"leap test" fails if shorewall is not installed

and the "--continue" flag doesn't work in this circumstance:

testbot@greyhound:~/rewire_develop/rewire$ leap_develop test
E, [2014-08-28T11:33:42.707814 #850] ERROR -- net.ssh.authentication.agent[15bbc64]: could not connect to ssh-agent
 = [rewdevmonitor1.rewire.org] PASS: Network > Can connect to internet?
 = [rewdevmonitor1.rewire.org] PASS: Network > Is stunnel running?
 = [rewdevmonitor1.rewire.org] ERROR: Network > Is shorewall running? [network.rb:58]:
 = [rewdevmonitor1.rewire.org]   Errno::ENOENT: No such file or directory - /sbin/shorewall status
 = [rewdevmonitor1.rewire.org]   /srv/leap/bin/run_tests:319:in ``'
 = [rewdevmonitor1.rewire.org]   /srv/leap/bin/run_tests:319:in `assert_run'
 = [rewdevmonitor1.rewire.org]   /srv/leap/tests/white-box/network.rb:58:in `test_03_Is_shorewall_running?'
 = [rewdevmonitor1.rewire.org] Tests halted on error (because of --no-continue).

Capistrano::CommandError: failed: "sh -c '/srv/leap/bin/run_tests'" on rewdevmonitor1.rewire.org
testbot@greyhound:~/rewire_develop/rewire$ leap_develop test --continue
E, [2014-08-28T11:33:50.575023 #861] ERROR -- net.ssh.authentication.agent[11dfbf4]: could not connect to ssh-agent
 = [rewdevmonitor1.rewire.org] PASS: Network > Can connect to internet?
 = [rewdevmonitor1.rewire.org] PASS: Network > Is stunnel running?
 = [rewdevmonitor1.rewire.org] ERROR: Network > Is shorewall running? [network.rb:58]:
 = [rewdevmonitor1.rewire.org]   Errno::ENOENT: No such file or directory - /sbin/shorewall status
 = [rewdevmonitor1.rewire.org]   /srv/leap/bin/run_tests:319:in ``'
 = [rewdevmonitor1.rewire.org]   /srv/leap/bin/run_tests:319:in `assert_run'
 = [rewdevmonitor1.rewire.org]   /srv/leap/tests/white-box/network.rb:58:in `test_03_Is_shorewall_running?'
 = [rewdevmonitor1.rewire.org] 3 tests: 2 passes, 0 skips, 0 warnings, 0 failures, 1 errors

(from redmine: created on 2014-08-28, closed on 2014-09-03, relates #6029 (closed))