Allow video id of 0 to be played without reloading

@BrettASwift The intro cinematic was being reloaded after the main menu, since its id was 0. This should fix that. ( I only noticed because it would hang on a black screen until I paused/unpaused in the dev window. Looks like it happens for me whenever it needs to load a video on the spot. Not sure why that's the case, or if it's happening for anyone else. )