[kronolith] Posible fix to Icalendar/itip errors...

[Sebastián Calero]

This works with the following changes in 'kronolith/lib/api.php':
 

189c189,191

< return $kronolith->getUID($eventId);

---

> $event = &$kronolith->getEvent($eventId);

> 

> return $event->getUID();

 

Greetings and thanks.

 

Sebastian Calero.