FreeBSD Handbook: Update obsolete/insecure http links to https

[marieheleneka_gmail.com]

Summary

Updating stale http:// links with https:// links in the FreeBSD handbook (English).

Event: EuroBSDCon 2026

[bcr]

Great, keep it up!

[marieheleneka_gmail.com]

Added more URLs to be updated. I've done a brief manual test of each new url to verify it works.

[marieheleneka_gmail.com]

Forgot to pass --staged when creating previous patch, so the previous patch only had the stuff I didn't want committed yet. Oops. :)

[bcr]

Looks good to me. Thank you!