Fix GLX < 1.3 window close.
Fix GLX < 1.3 window close.

adamlwgriffiths/Pyglet,seeminglee/pyglet64,seeminglee/pyglet64,seeminglee/pyglet64,niklaskorz/pyglet,adamlwgriffiths/Pyglet,niklaskorz/pyglet,niklaskorz/pyglet,niklaskorz/pyglet,adamlwgriffiths/Pyglet,adamlwgriffiths/Pyglet