macOS: openGL vout not compatible with GMA 950 graphics card

VLC on macOS does not support the Intel GMA 950, which has only openGL 1.4 support, because we require 2.0.

Still, they are machines which what GPU still running the 3.x branch.

See from mailing list:

Hi. Updated to 10.7.5, and downloaded the latest VLC update. However,
I still have problems playing videos. Since I can't get a crash log, I
will instead send a video. There is a flickering display happening
when playing videos (even 360p) on OSX 10.7.5 (A1181, mid-2007, Intel
GMA 950, 2.16GHz Core 2 Duo). I tried turning off Hardware Decoding
and yet it persist. Thanks.