roller: fix length in hex-encoded hash-transaction
roller: fix length in hex-encoded hash-transaction

urbit/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,urbit/urbit,urbit/urbit