Error when TZID=W. Europe Standard Time

In version 2.5.0, when using an ical export from thunderbird, the calendar is not loaded. The issue does not reproduce on 2.4.6 (before the ical4j upgrade).

This is because the TZID field is `W. Europe Standard Time`, which is not recognized by ical4j as a valid TZID.

Steps to reproduce:

1. Install fullcalendar version 2.5.0
2. On the sandbox page, add the ical from this issue as an attachment
3. On the sandbox page, add this to the content

   {{calendar iCal="http://localhost:8080/xwiki/bin/download/Sandbox/WebHome/calendar-test-weurope.ics"/}} 

The calendar should have an event on 19 Nov 2025, but it isn't displayed, event though the notification shows calendar was imported successfully.