Because of security concerns (WordPress sites are often targets), the only way to access an https webpage is from within the Fermilab Network including a VPN.
There are other things in LArSoft that require being within the Fermilab network (such as the Continuous Integration information), so, if possible, consider accessing the Fermilab network via a VPN. Instructions are available https://vpn.fnal.gov/. Access requires a Fermilab services account. Information on that is available here.
If that is not possible, please contact a member of the SciSoft team.