package/botan: security bump to version 2.19.3

Fix CVE-2022-43705: In Botan before 2.19.3, it is possible to forge OCSP
responses due to a certificate verification error. This issue was
introduced in Botan 1.11.34 (November 2016).

https://github.com/randombit/botan/security/advisories/GHSA-4v9w-qvcq-6q7w
https://github.com/randombit/botan/blob/2.19.3/news.rst



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>