update version to 1.975 (#4470)
update version to 1.975 (#4470)


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