After upgrading Confluence 5.9 Ajax call doesn't work anymore

[Zhifeng_Wu]

Our plugin stop working after Confluence 5.9

this.init = function(){
    var what = this;
    _self.restBase = AJS.params.baseUrl + '/rest/confluencecalendar/1.0';
    this.fullCalendar = AJS.$('#calendar').fullCalendar({
        header: {
            left: 'month,agendaWeek',
            center: 'title',
            right: 'today prev,next'
        },
        editable: false,
        eventClick: this.eventClicked,
        events: {
               url: _self.restBase + '/eventsOnPage',
               type: 'GET',
               data: {
                   pageId: AJS.params.pageId,
               },
               error: function() {
                   AJS.messages.error({
                       title: AJS.I18n.getText("event.error"),
                       body: AJS.I18n.getText("event.error.retrieve")
                   });
               }
           }
    });
};