shorewall: #2399 blocks uplink

With the fix #2399 (closed) shorewall restarts ok and we don't have any deployment issues anymore, BUT the uplink via eth0 is blocked. we still can deploy/ssh to the node via it's configured IF eth1, but we should fix the uplink issue.

(from redmine: created on 2013-06-14, closed on 2013-09-19, relates #4157 (closed))