[sess] Attempt to fix Symfony 2.6 PDO error
[sess] Attempt to fix Symfony 2.6 PDO error

ratchetphp/Ratchet,krageon/Ratchet,sudarshan955/Ratchet,cesarmarinhorj/Ratchet,vinod1988/Ratchet,b-viguier/Ratchet,KSDaemon/Ratchet,Jumplead/Ratchet,IRlyDontKnow/Ratchet,naroga/Ratchet,Nek-/Ratchet,zjien/Ratchet,ctkjose/Ratchet,mbonneau/Ratchet