[gnome-flashback] monitor-manager: remove persistent_timeout on dispose

[Alberts Muktupāvels <muktupavels src gnome org>]

commit f7908efd6d36616e02a0ff1ff7dbb6f484f5110f
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Mon Sep 13 14:46:23 2021 +0300

    monitor-manager: remove persistent_timeout on dispose
    
    Based on mutter commit:
    https://gitlab.gnome.org/GNOME/mutter/-/commit/b3c5ca12a585

 backends/gf-monitor-manager.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/backends/gf-monitor-manager.c b/backends/gf-monitor-manager.c
index 707eb45..969ac0d 100644
--- a/backends/gf-monitor-manager.c
+++ b/backends/gf-monitor-manager.c
@@ -2292,6 +2292,12 @@ gf_monitor_manager_dispose (GObject *object)
       priv->bus_name_id = 0;
     }
 
+  if (priv->persistent_timeout_id != 0)
+    {
+      g_source_remove (priv->persistent_timeout_id);
+      priv->persistent_timeout_id = 0;
+    }
+
   g_clear_object (&manager->display_config);
   g_clear_object (&manager->config_manager);