[nebula] fixed typo (#4528)
[nebula] fixed typo (#4528)

(cherry picked from commit c8fe6df79c1dd601116de9755bc06352ad6a691b)

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