The HTML file generated by the iteration export loads Javascript and
CSS resources from www.prismmodelchecker.org. Previously, those URLs
used http as the protocol. If such a generated HTML file was loaded
via an https-connections, current browsers would reasonably block
access to the Javascript, as it's not be loaded over a secure
connection.
As the prismmodelchecker.org site now supports https, we switch to
https for loading those resources.