[gnome-control-center] printers: Remove redundant variable set to NULL

[Marek Kašík <mkasik src gnome org>]

commit 2c4643663680edc398d7d1d4c2da962b9255bad6
Author: Robert Ancell <robert ancell canonical com>
Date:   Tue Nov 24 12:24:38 2020 +1300

    printers: Remove redundant variable set to NULL

 panels/printers/pp-new-printer-dialog.c | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/panels/printers/pp-new-printer-dialog.c b/panels/printers/pp-new-printer-dialog.c
index de410a868..fc1a5a16d 100644
--- a/panels/printers/pp-new-printer-dialog.c
+++ b/panels/printers/pp-new-printer-dialog.c
@@ -1908,7 +1908,6 @@ ppd_selection_cb (GtkDialog *_dialog,
   ppd_name = pp_ppd_selection_dialog_get_ppd_name (self->ppd_selection_dialog);
   ppd_display_name = pp_ppd_selection_dialog_get_ppd_display_name (self->ppd_selection_dialog);
   g_clear_object (&self->ppd_selection_dialog);
-  self->ppd_selection_dialog = NULL;
 
   if (ppd_name)
     {