handle null config in device level policy change
handle null config in device level policy change

MelvinTo/firewalla,firewalla/firewalla,firewalla/firewalla,firewalla/firewalla,firewalla/firewalla,MelvinTo/firewalla,MelvinTo/firewalla,firewalla/firewalla,MelvinTo/firewalla,MelvinTo/firewalla