Next HF activation code.

Summary: Fixed Nov, 13 so we are ready for whatever comes with 1x/2x .

Test Plan:

make check

Reviewers: freetrader, dagurval, sickpig, #bitcoin_abc, schancel

Reviewed By: #bitcoin_abc, schancel

Subscribers: schancel

Differential Revision: https://reviews.bitcoinabc.org/D612