[gnome-control-center] printers: Ensure objects are destroyed when dialog destroyed

[Marek Kašík <mkasik src gnome org>]

commit ce23d7e0b183641e26f28d952d77dac026a2acd9
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue Nov 24 12:31:21 2020 +1300

    printers: Ensure objects are destroyed when dialog destroyed

 panels/printers/pp-new-printer-dialog.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/panels/printers/pp-new-printer-dialog.c b/panels/printers/pp-new-printer-dialog.c
index fc1a5a16d..57de995c2 100644
--- a/panels/printers/pp-new-printer-dialog.c
+++ b/panels/printers/pp-new-printer-dialog.c
@@ -539,6 +539,8 @@ pp_new_printer_dialog_finalize (GObject *object)
   g_clear_pointer (&self->list, ppd_list_free);
   g_clear_object (&self->builder);
   g_clear_pointer (&self->local_cups_devices, g_ptr_array_unref);
+  g_clear_object (&self->ppd_selection_dialog);
+  g_clear_object (&self->new_device);
   g_clear_object (&self->local_printer_icon);
   g_clear_object (&self->remote_printer_icon);
   g_clear_object (&self->authenticated_server_icon);