Tracking unbound1.9

[Sylvain Beucler <beuc@beuc.net>]

Hi,

I saw a batch of new CVEs were tracked for 'unbound', but not for the 
stretch-specific 'unbound1.9' package[1].

I can go ahead and add '- unbound1.9' entries in data/CVE/list but I'm 
not sure whether that's what we want. Should I?

[1] https://lists.debian.org/debian-lts/2021/02/threads.html#00023

Cheers!
Sylvain