Make it so players can't leave in Ranked


Players disconnecting while picking characters or waiting for the map load up in Ranked is extremely annoying in Legacy (and probably in Stage 2 when enough people start getting to level 20). So while one of those screens is up, prevent players from backing out. No closing app (unless it crashes) either. But once a game starts (Hunters on the dropship or Monster feeding), then they can leave if they want.