Fix post_start_hooks entry point, add purge to setup hook

post_start_hooks was calling post_setup_hooks,
which is a misnomer. post_setup_hooks should also
call purge because it is necessary during upgrades.

Change-Id: Ic8731f185338b6febd9c543f837ffed2abec80a5
Partial-Bug: #1349287

deployment/puppet/docker/templates/dockerctl.erb

@@ -117,7 +117,7 @@ elif [ "$1" == "logs" ]; then
   logs $container
 elif [ "$1" == "post_start_hooks" ]; then
   shift 2
-  post_setup_hooks "$container" "$@"
+  post_start_hooks "$container" "$@"
 else
   echo "Invalid selection."
   show_usage

deployment/puppet/docker/templates/functions.sh.erb

@@ -393,6 +393,7 @@ function pre_start_hooks {
 }
 
 function post_setup_hooks {
+  purge_stale_iptables_rules $1
   case $1 in
     cobbler)   setup_dhcrelay_for_cobbler
                ;;