Apply cherry-pick before cmake

Summary:
Running cmake before cherry-picking D7771 will result in the build
not picking up the change.

Test Plan:

rm -rf .user-doc-cache/0.22.3                     # this ensures we will rebuild 0.22.3 docs
rm -rf .user-doc-cache/bitcoin-abc/build_0.22.3   # this ensures our build cache is clean
./fetch_documentation.sh

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D7785