Calendar is not loading in Firefox

[oanalavinia]

Opening Calendar app is not showing any calendar

In Chrome the problem is not reproduced.

Tested with Mocca Calendar version 2.8.9

[oanalavinia]

The issue is caused by #33 , namely 3c4e013#diff-2922c45d87c592fd9fb7ccef74b86f91R1135 this event is not firing in Firefox