Movie mode: special stage intro fade recording fix

This fixes GIFs/APNGs/etc not recording the extension to the special stage intro fades, where the screen stays white for an extra second or so.

Beep beep, @toaster is this fine to go in as it is? Or do you still want me to make it more efficient first or whatever it was you wanted (tbh I forgot exactly)?

merged

mentioned in commit 6c7acdbd