[nautilus] placesview: synchronize with GTK+

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

commit 6ce78e8dca480ca37b4c35f0ef1e59211a909ecb
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Tue Apr 11 16:58:17 2017 -0300

    placesview: synchronize with GTK+

 src/gtk/nautilusgtkplacesview.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/src/gtk/nautilusgtkplacesview.c b/src/gtk/nautilusgtkplacesview.c
index bccebea..523008b 100644
--- a/src/gtk/nautilusgtkplacesview.c
+++ b/src/gtk/nautilusgtkplacesview.c
@@ -417,7 +417,11 @@ nautilus_gtk_places_view_destroy (GtkWidget *widget)
     priv->destroyed = 1;
 
     g_signal_handlers_disconnect_by_func (priv->volume_monitor, update_places, widget);
-    g_signal_handlers_disconnect_by_func (priv->network_monitor, update_places, widget);
+
+    if (priv->network_monitor)
+    {
+        g_signal_handlers_disconnect_by_func (priv->network_monitor, update_places, widget);
+    }
 
     g_cancellable_cancel (priv->cancellable);
     g_cancellable_cancel (priv->networks_fetching_cancellable);