By Emma Gritt Travis Scott was forced to postpone his gig in Chicago last night due to issues with his private jet. The rapper, 32, enraged fans when he announced via Instagram that his show at the United Center wasn’t going ahead – just hours before he was due on stage. The statement read: “Travis Scott’s show at United Center scheduled for tonight has been postponed. All previously purchased tickets will be honored for the new date once announced. More information will be posted here and emailed to ticket holders directly when available.” Fans were quick to take to the comments to vent their…