tests: fix tests broken under GETTEXT_POISON=YesPlease

tests: fix tests broken under GETTEXT_POISON=YesPlease

The GETTEXT_POISON=YesPlease compile-time testing option added in my
bb946bba76 ("i18n: add GETTEXT_POISON to simulate unfriendly
translator", 2011-02-22) has been slowly bitrotting as strings have
been marked for translation, and new tests have been added without
running it.

I brought this up on the list ("[BUG] test suite broken with
GETTEXT_POISON=YesPlease", [1]) asking whether this mode was useful at
all anymore. At least one person occasionally uses it, and Lars
Schneider offered to change one of the the Travis builds to run in
this mode, so fix up the failing ones.

My test setup runs most of the tests, with the notable exception of
skipping all the p4 tests, so it's possible that there's still some
lurking regressions I haven't fixed.

1. <CACBZZX62+acvi1dpkknadTL827mtCm_QesGSZ=6+UnyeMpg8+Q@mail.gmail.com>

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>