[metacity] libmetacity: fix memory leak

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 36ef44dd4d79501dc5962bf7923e5fcf9308e4a3
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sat Jan 11 17:00:53 2020 +0200

    libmetacity: fix memory leak
    
    https://gitlab.gnome.org/GNOME/mutter/commit/c13ea4f48ddbb8dfe67acc

 libmetacity/meta-theme-gtk.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/libmetacity/meta-theme-gtk.c b/libmetacity/meta-theme-gtk.c
index aeedba6d..93723067 100644
--- a/libmetacity/meta-theme-gtk.c
+++ b/libmetacity/meta-theme-gtk.c
@@ -878,6 +878,7 @@ meta_theme_gtk_draw_frame (MetaThemeImpl           *impl,
 
               g_assert (pixbuf == NULL);
               pixbuf = gtk_icon_info_load_symbolic_for_context (info, context, NULL, NULL);
+              g_object_unref (info);
             }
 
           if (pixbuf)