The function under test by the StrftimeLocalizedHtmlTest checks the
timezone in the user preferences of the user making the request. If we
don't explicitly set a request here, it will simply use the last Request
that `crum` cached in the thread local cache. This broke now
that we sometimes set the crum request.user to an invalid user in other
tests.
This change ensures that we have a valid request for these tests as a
part of the setup of this test class.
4f9fe59731