[CMAKE] Improve FindZeroMQ
Summary:
The minimum version is set to 4.1.5 (2016) due to a bugfix for
ZMQ_LINGER. This is also the version from the depends.
Test Plan:
ninja check
Run the Gitian builds.
Reviewers: #bitcoin_abc, jasonbcox
Reviewed By: #bitcoin_abc, jasonbcox
Differential Revision: https://reviews.bitcoinabc.org/D5454