remote-mediawiki tests: use inline PerlIO for readability
Replace the use of the "open" pragma with a three-arg open in the
places that actually care about UTF-8, while leaving those that
don't (the config parsing).
Unlike the previous "encoding" pragma change this isn't needed for
compatibility with anything. I just think it's easier to read code
that has localized effects than code that changes global settings.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>