fix event dragging
fix event dragging

Event dragging was broken after resources ajax loading implemented

tbuckel/fullcalendar,tojocky/fullcalendar,leniel/fullcalendar,lomaxx/fullcalendar,arenoir/fullcalendar,tbuckel/fullcalendar,pkasperski/fullcalendar,leniel/fullcalendar,pkasperski/fullcalendar,lphuberdeau/fullcalendar,tojocky/fullcalendar,lphuberdeau/fullcalendar,kapouer/fullcalendar,lomaxx/fullcalendar,kapouer/fullcalendar,stephenreid/fullcalendar,stephenreid/fullcalendar,tojocky/fullcalendar,arenoir/fullcalendar