[horde] Use Nextcloud calender subscriptions in Horde

[Twilek]

Hi all,

I try to subscripe to a public Nextcloud calendar. They come in the  
form of a URL like that:

"webcal://www.ahlhauser-hammer.de/nextcloud/remote.php/dav/public-calendars/6K8S4FL9MRQ49443?export"

That Horde does not understand. Changing "webcal" to "https" and  
entering that in a browser will yield a download of
"6K8S4FL9MRQ49443.ics" with the calendar info included

This works with Google Calender and similar calendars but not with  
Horde ("Ressource not found"). It seems that Horde needs a direct link  
to an .ics file.

Is there anything I can do to make horde accept that redirect (I guess  
that is what that is in the end).

Regards

Henning