In scope of the work for https-first mode, mochitests are update in order to work when https-first is enabled. https://bugzilla.mozilla.org/show_bug.cgi?id=1704453

However this doesn't mean that all tests will only use https URLs at this point. When https-first is enabled, you can still open a tab pointing to a http URL, and it will transparently be upgraded to https.

As long as the test doesn't assert the URL anywhere, this will not fail in CI. However this creates a mismatch between the constants defined in the test and what will actually be loaded, which can ultimately be confusing.

After the tests have been updated to at least work with https-first, we should thoroughly update all test folders to only use https URLs.