Unfortunately, my understanding is that an actual http -> https redirect is not possible within WFA itself. You could use a load balancer or something of the sort in front of it for that purpose, I suppose.
However, in my environment I just disabled http and gave my users the https link. In case anyone needs the process: https://library.netapp.com/ecmdocs/ECMP1644817/html/GUID-91691512-8172-4190-9BFF-C638C978DABE.html
All, if something has changed with this process or with the redirect possibilities, please share that info.
Let me know if that helps at all.