source-dialog: clear previously unsaved calendars

src/gcal-source-dialog.c

@@ -340,6 +340,13 @@ select_calendar_file (GtkButton *button,
 
       file = gtk_file_chooser_get_file (GTK_FILE_CHOOSER (dialog));
 
+      /**
+       * Remove any reminescent ESources
+       * cached before.
+       */
+      if (priv->local_source != NULL)
+        g_clear_pointer (&(priv->local_source), g_object_unref);
+
       /**
        * Since we cannot guarantee that the
        * type system registered ESourceLocal,