Python 3d_viewer: init glut manually for windows ( https://github.com/assimp/assimp/issues/622 ).

port/PyAssimp/scripts/3d_viewer.py

@@ -68,7 +68,7 @@ class PyAssimp3DViewer:
         pygame.init()
         pygame.display.set_caption(self.base_name)
         pygame.display.set_mode((w,h), pygame.OPENGL | pygame.DOUBLEBUF)
-
+        glutInit()
         self.prepare_shaders()
 
         self.cameras = [DefaultCamera(w,h,fov)]