kolab-util-calendar: allow the (X)FB trigger code to read Kolab password
kolab-util-calendar: allow the (X)FB trigger code to read Kolab password

* when creating the (X)FB update trigger, which is a HTTP request,
  we need to know the Kolab user password for HTTP basic auth
* so we temporarily expose the password, pull the trigger, and
  hide the password again

GNOME/evolution-kolab,GNOME/evolution-kolab