Don't download OpenSSL from ftp.openssl.org anyomre

[KJTsanaktsidis]

OpenSSL announced that they're changing how they handle releases in this blog post: https://openssl.org/blog/blog/2024/04/30/releases-distribution-changes/

The tl;dr is that:

• ftp.openssl.org is being shut down (even for HTTP access)
• The releases at openssl.org/source will redirect to github
• git.openssl.org is also shut down (the git repo is on github)

This commit just changes over to using openss.org/source instead of ftp.openssl.org. We might also need to switch to downloading directly from Github... let's see.

It also changes to cloning the head of openssl from github too.

[junaruga]

Thanks for the PR! It looks good to me!

[KJTsanaktsidis]

Thanks!