Description: Don't try to get properties if the interface doesn't have an owner yet, to break a loop when whoopsie-preferences exits.
Author: Iain Lane <iain.lane@canonical.com>

Index: b/src/diagnostics-widget.c
===================================================================
--- a/src/diagnostics-widget.c
+++ b/src/diagnostics-widget.c
@@ -179,6 +179,9 @@
                        const gchar* const* invalidated_properties,
                        gpointer user_data)
 {
+    if (!g_dbus_proxy_get_name_owner(interface))
+        return;
+
     WhoopsieDaisyPreferencesPrivate* priv = WHOOPSIE_DAISY_PREFERENCES (user_data)->priv;
     gboolean report_errors, report_metrics;
     GtkWidget* submit_error_reports = NULL;
