dictionary: replace deprecated gdk_flush

mate-dictionary/src/gdict-aligned-window.c

@@ -162,6 +162,7 @@ gdict_aligned_window_position (GdictAlignedWindow *window)
  gint x, y;
  GdkGravity gravity = GDK_GRAVITY_NORTH_WEST;
  GdkWindow *gdk_window;
  GdkDisplay *display;

  g_assert (GDICT_IS_ALIGNED_WINDOW (window));
  priv = window->priv;
@@ -172,7 +173,8 @@ gdict_aligned_window_position (GdictAlignedWindow *window)
  align_widget = priv->align_widget;
  gdk_window = gtk_widget_get_window (align_widget);

  gdk_flush ();
  display = gdk_display_get_default ();
  gdk_display_flush (display);

  gdk_window_get_geometry (gtk_widget_get_window (GTK_WIDGET (window)), NULL, NULL, &our_width, &our_height);