Add missing import sys to gl
Add missing import sys to gl

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