fix invalid memory access after unavailable reference frame insertion

fix invalid memory access after unavailable reference frame insertion

Origin: https://github.com/strukturag/libde265/commit/ee8e09a7f6f65b7c409c7801ad64918a2925ed9b
Reviewed-by: Tobias Frost <tobi@debian.org>
Last-Update: 2023-01-24 <YYYY-MM-DD, last update of the meta-information, optional>

Needed to avoid asan errors for the version at hand, otherwise the crash even
happens before the pocs triggers.
Last-Update: 2023-01-24 <YYYY-MM-DD, last update of the meta-information, optional>
Gbp-Pq: Name fix-invalid-memory-access.patch