Justin Bieber has branded an online troll a “sad excuse of a human” for encouraging people to insult his wife Hailey Bieber.The Sorry hitmaker blasted the social media user who was trying to convince fans of his previous romance with Selena Gomez to “go after” his wife with cruel messages and comments.Responding in a lengthy post on his Instagram Story, he wrote: “This sad excuse of a human just encouraged people on video to literally go after my wife telling people to say that my previous