qtvideosink/OpenGLSurfacePainter: Define GL_CLAMP_TO_EDGE if not already defined
qtvideosink/OpenGLSurfacePainter: Define GL_CLAMP_TO_EDGE if not already defined

Some windows environments apparently have way out of date OpenGL headers
that do not even support OpenGL 1.2.

nasserGanjali/QtGStreamer,comicfans/libqtgstreamer,detrout/qt-gstreamer,dejunk/gstreamer,GStreamer/qt-gstreamer,iperry/qt-gstreamer,GStreamer/qt-gstreamer,comicfans/libqtgstreamer,ylatuya/qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,dejunk/gstreamer,knuesel/qt-gstreamer,tswindell/qt-gstreamer,ylatuya/qt-gstreamer,nasserGanjali/QtGStreamer,comicfans/libqtgstreamer,iperry/qt-gstreamer,nasserGanjali/QtGStreamer,detrout/qt-gstreamer,GStreamer/qt-gstreamer,knuesel/qt-gstreamer,tswindell/qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,knuesel/qt-gstreamer,detrout/qt-gstreamer,tswindell/qt-gstreamer,ylatuya/qt-gstreamer,dejunk/gstreamer,iperry/qt-gstreamer