Subscribe via URL does not work with iCloud Calendar format

Reproduction steps:

1. Clean Install of Confluence 5.6.5
2. Clean Install of Team Calendars 5.1.7
3. Build an iCloud Calendar, share it publicly
4. Gather the webcal URL from iCloud
5. Go to configure Team Calendars, Subscribe by URL

• Try the URL: webcal://p29-calendarws.icloud.com/ca/subscribe/1/ylFkt2Busa4o9Y-5TIDGL1tXOsin82JyqCIun8t1amMo0PC97k4DZMZ84YsSdiGb
• Try as an http URL
• Try as an https URL
• All attempts fail to connect as the error message is thrown in the attached images hereto

Expected behavior

As this is an Apple iCloud calendar and is specifically an ical Calendar, it should work, even though the URL is obfuscated for the principal folder where the Calendar resides. iCloud is a popular calendar and one which we should expect to work for clients.

Actual behavior

Actual behavior is such that the URL does not fetch from a wget, in fact the output is somewhat disheartening (screen4.png - attached).

It does work on a Mac, but not in Team Calendars.

Related Notes

Some people have hacked DNS to build entries to their shared calendars and hacked Google to build a shareable URL with Google calendars: http://icaltogcal.com, but nothing seems to work with Team Calendars. Suppose a workaround might be to import it into Google Calendars and share that, but that is a hack, not really a solution that offers the Subscribe by URL method that is offered.

Workaround

http and https prefix are now working for iCloud calendar subscription: change prefix from webcal to http or https to subscribe in Team Calendars.
For example:

• webcal://p29-calendarws.icloud.com/ca/subscribe/1/ylFkt2Busa4o9Y-5TIDGL1tXOsin82JyqCIun8t1amMo0PC97k4DZMZ84YsSdiGb

change to:

• http://p29-calendarws.icloud.com/ca/subscribe/1/ylFkt2Busa4o9Y-5TIDGL1tXOsin82JyqCIun8t1amMo0PC97k4DZMZ84YsSdiGb