fixed compat with Symfony 2.7
fixed compat with Symfony 2.7

silexphp/Silex,fabpot/Silex,romainneutron/Silex,fabpot/Silex,romainneutron/Silex,mTorres/Silex,mTorres/Silex,romainneutron/Silex,gencer/Silex