Correctd orientation of sash handle.

Adapted some code in the native scrolling window
    to the generic version's code.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30979 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/renderer.cpp

@@ -353,7 +353,7 @@ wxRendererGTK::DrawSplitterSash(wxWindow *win,
         rect.y,
         rect.width,
         rect.height,
-        isVert ? GTK_ORIENTATION_VERTICAL : GTK_ORIENTATION_HORIZONTAL
+        !isVert ? GTK_ORIENTATION_VERTICAL : GTK_ORIENTATION_HORIZONTAL
     );
 #else // GTK+ 1.x