OPENGL32: Fix missing prototypes when using nVidia OpenGL headers

[H. Verbeet]

Changelog:
 - Fix missing prototypes when using nVidia OpenGL headers

Index: dlls/opengl32/opengl_ext.h
===================================================================
RCS file: /home/wine/wine/dlls/opengl32/opengl_ext.h,v
retrieving revision 1.8
diff -u -r1.8 opengl_ext.h
--- dlls/opengl32/opengl_ext.h	13 May 2005 13:59:00 -0000	1.8
+++ dlls/opengl32/opengl_ext.h	27 Sep 2005 23:22:37 -0000
@@ -24,6 +24,7 @@
 #undef WINAPI

 #define XMD_H /* This is to prevent the Xmd.h inclusion bug :-/ */
+#define GL_GLEXT_PROTOTYPES
 #include <GL/gl.h>
 #include <GL/glx.h>
 #ifdef HAVE_GL_GLEXT_H