Incorrect stop transaction id when fixing out of order timestamps in history store

/*         

 * We're going to be inserting something immediately after with the same timestamp. Either         

 * another moved update OR the update itself that triggered the correction. In either case,         

 * we should preserve the stop transaction id.        

 */        

hs_insert_tw.stop_ts = hs_insert_tw.durable_stop_ts = ts;        

hs_insert_tw.stop_txn = hs_cbt->upd_value->tw.start_txn;