fix tests to enforce antireplay OP_RETURN on first byte only
fix tests to enforce antireplay OP_RETURN on first byte only

Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Bitcoin-com/BUcash,Bitcoin-com/BUcash,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Bitcoin-com/BUcash,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,Bitcoin-com/BUcash,BitcoinUnlimited/BitcoinUnlimited,Bitcoin-com/BUcash,Bitcoin-com/BUcash,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited