We should get either dive trailer or dive profile immediately after
header. Thus make sure that is the case.
Signed-off-by: Miika Turkia <miika.turkia@gmail.com>
This is first step towards parsing "empty" dives properly. I.e. now the
updated test dive parses properly.
Signed-off-by: Miika Turkia <miika.turkia@gmail.com>