docker-parity: ignore sanity check if baseImage history is null
docker-parity: ignore sanity check if baseImage history is null

Docker still builds image and adds history even if baseImage history is
null lets follow that

Signed-off-by: Aditya R <4f9683854fe0b71db89677d592545c6b565c2266@redhat.com>

TomSweeneyRedHat/buildah,TomSweeneyRedHat/buildah,TomSweeneyRedHat/buildah,nalind/buildah-1,nalind/buildah-1,nalind/buildah-1