Arsenal legend Thierry Henry feels David Raya made a ‘basic’ error to let Ross Barkley score Luton Town’s third goal before the Gunners took a dramatic 4-3 win on Tuesday. Barkley gave the Hatters a shock lead on 57 minutes at Kenilworth Road as Luton came from behind against Arsenal. But Kai Havertz (60’) and Declan Rice (90+7’) replied in a theatrical fashion. Rice headed home Martin Odegaard’s cross in the last meaningful act of the fixture. Gabriel Martinelli (20’) and Gabriel Jesus (45’) had twice given the Gunners the lead away to Luton. But Gabriel Osho (25’) and Elijah Adebayo (49’) pu…