Update performance graphics error message description

[Keul]

http://steamcommunity.com/sharedfiles/f ... =297732136 (screenshot is safe for work)

Maybe it's time to work on this error message (as my friend said, saying that graphics are displayed slowly on high-end config seems strange). Maybe we should replace the first sentence with «there is a performance problem with the graphics system»

Also, how is that possible to happen on high-end config?

[PyTom]

I think it's an accurate message.

That particular message is produced if the graphics system can't display 5 frames in a row at better than 15 fps. It's likely that if you see that, you're using software GL for some reason, which is slow.