Avoid probable race condition

icwmpd has an external firewall.cwmp firewall hook to create firewall rules for incoming connection requests. icwmpd used to detects the ip change for the ACS and reload the firewall, which in turn calls the external firewall.cwmp hook, before sending the packets out. In slow system, this could very well can create a race condition as there's a delay in firewall reload and applying of external hook.

This change avoid restarting the firewall if connection request policy is based on port only, otherwise it selectively calls the external hook to avoid apply delays.