Some files with no image items have them, and were working prior to the recent
HEIF parsing overhaul.
Ignore such boxes instead, to recover the old behavior.
Fixes a regression since d9fed9df2a.
Tested-by: Wu Jianhua <toqsxw@outlook.com>
Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit 5b9db32ccc)