"remove" is not entirely correct. But at least the function is aware
that if the given repo is not the_repository, then $CWD and
is_inside_work_tree() means nothing.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>