window: set edit dialog's event to NULL after saving

Earlier the app used to crash when a new event was added using the
'Edit Details' buttion/dialog. This was happening because edit dialog's
event was set to NULL before the event was being stored in the calendar
through the 'edit_dialog' and hence the app was crashing.

This patch fixes the above-mentioned issue by saving the event before
setting the edit dialog's event to NULL.

https://bugzilla.gnome.org/show_bug.cgi?id=779733

src/gcal-window.c

@@ -1135,7 +1135,6 @@ edit_dialog_closed (GtkDialog *dialog,
   event = gcal_edit_dialog_get_event (edit_dialog);
   view = GCAL_VIEW (window->views[window->active_view]);
 
-  gcal_edit_dialog_set_event (edit_dialog, NULL);
   gtk_widget_hide (GTK_WIDGET (dialog));
 
   switch (response)
@@ -1182,6 +1181,8 @@ edit_dialog_closed (GtkDialog *dialog,
       break;
 
     }
+
+  gcal_edit_dialog_set_event (edit_dialog, NULL);
 }
 
 static void