Revert "scrolledwindow: Remove child before destroying self"

This reverts commit dcb4b48b29.

This was causing crashes in the filechooser in some applications.

https://bugzilla.gnome.org/show_bug.cgi?id=766694

gtk/gtkscrolledwindow.c

@@ -2672,11 +2672,6 @@ gtk_scrolled_window_destroy (GtkWidget *widget)
 {
   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
-  GtkWidget *child;
-
-  child = gtk_bin_get_child (GTK_BIN (widget));
-  if (child)
-    gtk_container_remove (GTK_CONTAINER (widget), child);
 
   remove_indicator (scrolled_window, &priv->hindicator);
   remove_indicator (scrolled_window, &priv->vindicator);