Fix software vsync
This pre-SDL 2.0.18 hack from the interp branch is no longer needed when building with a new enough SDL version. This makes vid_wait toggleable at all times if SDL is at least 2.0.18.
This pre-SDL 2.0.18 hack from the interp branch is no longer needed when building with a new enough SDL version. This makes vid_wait toggleable at all times if SDL is at least 2.0.18.