security/sequoia-sq: fix LICENSE

Upstream forgot to update sq's licence upon relicensing all of
sequoia in October 2021; correct metadata here as well.

https://gitlab.com/sequoia-pgp/sequoia-sq/-/commit/dcea72208a095fd7b99faf365a3e55e2b68f72cf
(cherry picked from commit bbb3f108a25a668541493671ecd52d5bdb77f24e)