Fix leakage of old books.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@13769 57a11ea4-9604-0410-9ed3-97b8803252fd

lib/libqof/qof/qofsession.c

@@ -1130,8 +1130,8 @@ qof_session_load (QofSession *session,
 		qof_book_set_backend (ob, NULL);
 		qof_book_destroy (ob);
 	}
-        /* Um, I think we're leaking the oldbooks list. */
-	
+	g_list_free (oldbooks);
+
 	LEAVE ("sess = %p, book_id=%s", session, session->book_id
          ? session->book_id : "(null)");
 }