configure: Fixed bug in previous OpenGL warning patch.
diff --git a/configure.ac b/configure.ac
index 806c840..b327e0b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -410,7 +410,7 @@
 	      )
             )
 
-	    if test "$wine_cv_opengl_version_OK" = "yes"
+	    if test "$wine_cv_opengl_header_version_OK" = "yes"
             then
 		dnl Check for the presence of the library
 		AC_CHECK_LIB(GL,glXCreateContext,