Simplify "!foo || (foo && bar)" as "!foo || bar"

Summary: Backport of core PR10780

Test Plan:

make check

Reviewers: #bitcoin_abc, deadalnix, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Subscribers: teamcity, schancel

Differential Revision: https://reviews.bitcoinabc.org/D2198