[ecash-herald] Parse new miner

Summary:
From the payout address, this guy has been mining for some time, but used to be ckpool in the coinbase

now we have been parsing as unknown. correct to reflect the /node/ string in the coinbase

Test Plan: npm test

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D18373