iptables rule for heat pip mirror

This is required for guest VMs to reach http://$HOST_IP:8899

Change-Id: I814c682fb02974ae05dfbe5e212409cdd11d16ac
diff --git a/lib/heat b/lib/heat
index c7abd3b..a27691f 100644
--- a/lib/heat
+++ b/lib/heat
@@ -337,6 +337,7 @@
     " -i $heat_pip_repo_apache_conf
     enable_apache_site heat_pip_repo
     restart_apache_server
+    sudo iptables -I INPUT -d $HOST_IP -p tcp --dport $HEAT_PIP_REPO_PORT -j ACCEPT || true
 }
 
 # Restore xtrace