Manchester City sent a birthday message to Sergio Aguero at the weekend, and the Etihad Legend gave a response fans will love. Manchester City recently secured their fourth straight Premier League title, beating West Ham United on the final day of the season to edge out Arsenal. That was Pep Guardiola‘s sixth as City manager, and the eighth in the club’s history. The very first, of course, came back in 2012 – and it could not have arrived in more dramatic fashion. City fans will never forget the emotions of going 2-1 down against QPR, before turning it around to win and break Manchester United…