Merge #11997: [tests] util_tests.cpp: actually check ignored args

Summary:
c99a3c32c8 [tests] util_tests.cpp: actually check ignored args (Anthony Towns)

Pull request description:

An array with 7 elements was setup for checking argument parsing, but
was passed to ParseParamaeters with argc=5, meaning the interpretation
of the last two arguments was never actually checked.

Tree-SHA512: 7b81fde49742e524f1bb67e2ec084f5909ae36125f237f0210df4587c62e5a5a8f277f13543f0a85ad145c4bb80d62339a7d50d7ed41659df318c8198ea7f428

Backport of Core PR11997:
https://github.com/bitcoin/bitcoin/pull/11997/

Test Plan:

make check

Reviewers: deadalnix, Fabien, jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3707