Befor: I use Thunderbird/Lightning for my mails and for my calendar. This issue is about the calendar. I'm a google-user.
A short while ago I started to change from "Provider for Google's calendar" to the CalDAV way because I couldn't import invitations to my calendar. So far so good.
But now, every time I start Thunderbird or the calendar would like to synchronize it pops up the following window (for every calendar. I have 5!):
I could not find any preferences where I can say that Lightning can use it every time.
So, am I blind or how can I fix this?