opengl32: Exclude unused header

[Andrew Talbot]

Changelog:
    opengl32: Exclude unused header.

diff -urN a/dlls/opengl32/wgl.c b/dlls/opengl32/wgl.c
--- a/dlls/opengl32/wgl.c	2007-03-13 12:57:51.000000000 +0000
+++ b/dlls/opengl32/wgl.c	2007-05-15 22:04:55.000000000 +0100
@@ -28,7 +28,6 @@
 #include "windef.h"
 #include "winbase.h"
 #include "winuser.h"
-#include "winerror.h"
 #include "winreg.h"
 #include "wingdi.h"
 #include "winternl.h"