wrong implemention OP_RETURN in interpreter

[zhfnjust]

this test should pass:

    #[test]
    fn true_opreturn_false() {

        let script = Script::from_hex("516a00")
        .unwrap();

        let mut interpreter = Interpreter::from_script(&script);
        interpreter.run().unwrap();

        assert_eq!(interpreter.state().stack().last().unwrap(), &vec![1_u8]);
    }