Mark CHERRY_PICK_HEAD related messages in builtin/merge.c that were
added in v1.7.5-rc0~88^2~2 (Introduce CHERRY_PICK_HEAD) by Jay Soffian
for translation.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>