[Development] Wrong OpenGL version detection on Mac

[Massimo Callegari]

Hi devs,
I'm referring to https://bugreports.qt.io/browse/QTBUG-68130

Unfortunately it affects shaders in Qt3D, so it would be nice if this can be fixed on 5.11.0, if it's not too late.
Forcing the GL version with QSurfaceFormat doesn't help.

I haven't tested on 5.9.x, but I'm a bit surprised nobody spotted this before.

Cheers,
Massimo