OpenGL background sky texture scale

The background sky texture in OpenGL is not as tall as it is in Software.

added Bug OpenGL renderer labels

mentioned in merge request !1517 (merged)

mentioned in issue #753 (closed)

The scale of the sky texture seems to resize depending on what resolution you use in Software:

800x600

1366x768

1600x900

Either way it seems more a problem with Software than with OpenGL, where the size doesn't change depending on which resolution you use, unless OpenGL needs to replicate this effect.