[gtk] placessidebar: Remove popover using gtk_widget_unparent()

[Timm Bäder <baedert src gnome org>]

commit 002abc6d485b9173bf67f3bd606710c59ccb09a9
Author: Timm Bäder <mail baedert org>
Date:   Sun Aug 4 14:37:49 2019 +0200

    placessidebar: Remove popover using gtk_widget_unparent()
    
    the gtk_widget_destroy() does not work anymore.

 gtk/gtkplacessidebar.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/gtk/gtkplacessidebar.c b/gtk/gtkplacessidebar.c
index 25e99fa37a..2f5644a455 100644
--- a/gtk/gtkplacessidebar.c
+++ b/gtk/gtkplacessidebar.c
@@ -3667,8 +3667,7 @@ show_row_popover (GtkSidebarRow *row)
 
   g_object_get (row, "sidebar", &sidebar, NULL);
 
-  if (sidebar->popover)
-    gtk_widget_destroy (sidebar->popover);
+  g_clear_pointer (&sidebar->popover, gtk_widget_unparent);
 
   create_row_popover (sidebar, row);