By Ewan Murray Aston Villa have a mountain to climb this Thursday when they travel to Olympiacos in the second leg of their Europa Conference League semi-final. The 1982 European champions find themselves 4-2 down from the first leg at Villa Park, with a Ayoub El Kaabi hat-trick guiding the Greek side to victory. Ollie Watkins and Moussa Diaby did get on the scoresheet, but a late penalty miss from Douglas Luiz means the odds are stacked against Unai Emery’s side for the second leg. Villa also stumbled in their pursuit of Champions League qualification last Sunday, losing 1-0 away at Brighton….