Fix OverlayManager::getViewportAspectRatio, was inverted
Fix OverlayManager::getViewportAspectRatio, was inverted

--HG--
branch : v1-6

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