[ecash-herald] Patch bug in daily summary calc

Summary:
Typo resulting in getting last 48 hrs worth of blocks instead of 24, patch

The checker was working, but bc I was mixing up "yesterday" with "today" -- was passing "yesterday" into getAllBlockTxs, which then had to go back in time well more than 144 blocks to get the "right" (wrong) block.

Test Plan: npm test, confirm typo corrected and the "right" date is going into getAllBlockTxs

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D16945