[website] Update Electrum ABC daemon instructions with a better command

Summary: The listaddresses command is a better way to get addresses

Test Plan:
I used this command and found it's more convenient
Also ran the site locally and read through the changed version.

Reviewers: PiRK, #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Subscribers: bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D12851