Mikel Arteta has warned Arsenal to learn from their costly mistakes in Tuesday’s dramatic 2-2 draw against Bayern Munich if they want to reach the Champions League semi-finals. Arteta’s side ensured their quarter-final clash remains finely balanced thanks to Leandro Trossard’s late equaliser in the first leg at the Emirates Stadium. Arsenal’s old tormentor-in-chief Harry Kane had ignored a hostile reception from Gunners fans to mark his return to north London with the ice-cool penalty that put Bayern 2-1 up in the first half. Former Tottenham striker Kane’s sixth career goal at the Emirates came after ex-Arsenal winger Serge Gnabry cancelled out Bukayo…