Please describe the problem:
The plugin makes itself and Evolution unusable as soon as the CalDav-server isn't available anymore - not even when changing Evolution's status to Offline-operation. The Plugin blocks the whole Evolution interface, nothing reacts anymore for some seconds or even minutes. As soon as the Calendar is being opened or any backend of Evolution is trying to use the information provided by the CalDav calendar the whole software hangs up. Even when I just right-click the Calendar to delete it, the plugin blocks my whole evolution and it takes ages to delete one calendar.

Steps to reproduce:
1. Create a new CalDav-calendar
2. Plug the network-cable out of your machine
3. Try to work with Evolution


Actual results:


Expected results:


Does this happen every time?
Yes.

Other information:
Debian SID, Evolution 2.22.1;