Fix [3538257]: Listener was never actually removed in SceneManager::removeListener
Fix [3538257]: Listener was never actually removed in SceneManager::removeListener

--HG--
branch : v1-8

digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre,digimatic/ogre