[mutter] monitor-manager: Remove persistent_timeout on dispose

[Marge Bot <marge-bot src gnome org>]

commit b3c5ca12a5856306328ca43eabfbd738ead364a5
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Fri May 1 16:39:47 2020 +0200

    monitor-manager: Remove persistent_timeout on dispose
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1233>

 src/backends/meta-monitor-manager.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index e8e3a3c9ad..934a685077 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -1122,6 +1122,8 @@ meta_monitor_manager_dispose (GObject *object)
   g_clear_object (&manager->display_config);
   g_clear_object (&manager->config_manager);
 
+  g_clear_handle_id (&manager->persistent_timeout_id, g_source_remove);
+
   G_OBJECT_CLASS (meta_monitor_manager_parent_class)->dispose (object);
 }