[gnome-calendar] calendar: Disconnect from the visible signals as well

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit b49486d0f951e5b800970c81e08f4c5d5ce27897
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sat Jul 13 19:54:47 2019 -0300

    calendar: Disconnect from the visible signals as well
    
    Missed from the initial implementation.

 src/core/gcal-calendar.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/core/gcal-calendar.c b/src/core/gcal-calendar.c
index e385fa85..1e68d2c8 100644
--- a/src/core/gcal-calendar.c
+++ b/src/core/gcal-calendar.c
@@ -233,6 +233,7 @@ gcal_calendar_finalize (GObject *object)
   gcal_clear_signal_handler (&priv->color_changed_handler_id, selectable_extension);
   gcal_clear_signal_handler (&priv->name_changed_handler_id, priv->source);
   gcal_clear_signal_handler (&priv->readonly_changed_handler_id, priv->client);
+  gcal_clear_signal_handler (&priv->visible_changed_handler_id, selectable_extension);
 
   g_clear_object (&priv->client);
   g_clear_object (&priv->source);