Fix blocking SmallColorSelector on OpenGL 2.1, possibly other errors
Commit 10906539 made KisOpenGL::hasOpenGL3() always return true. This causes the Small Color Selector to be loaded on OpenGL 2.1, which for some reason crashes on the Intel graphics drivers when the pop-up palette is invoked (according to reports).
Requesting review from @dkazakov because I am just a little bit unsure if this is intentional or not.