[FIX] website_event_track: Tracks in the wrong room in the agenda

When setting an event tracks like this:
- Track 1, 10:00 to 10:30 Room A
- Track 2, 10:30 to 11:00 Room B
- Track 3, 11:00 to 11:30 Room A

In the agenda of the event, on the website, the Track 2
was displayed as in the Room A, while it should be in the Room B

opw-715480