gc: fix a memory leak
Fix a memory leak in code added in 41abfe15d95 (maintenance: add
pack-refs task, 2021-02-09), we need to call strvec_clear() on the
"struct strvec" that we initialized.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
authored by