Mk/bsd.sites.mk: Remove stale sites
- https://ftp.gnome.org is a permanent redirect to https://download.gnome.org which is already in the list
- https://cyberside.net.ee/tor/%SUBDIR%/ is a permanent redirect to https://cyberside.net.ee/sibul/dist/%SUBDIR%/
- https://torproject.crypto.is does not resolve
- https://mi.mirror.garr.it/ is defunct as all pages return 404
Approved by: portmgr (just-fix-it)