When I load the addons.mozilla.org page in Firefox, I see the following warning in the console: "Public-Key-Pins: The certificate used by the site was not issued by a certificate in the default root certificate store. To prevent accidental breakage, the specified header was ignored." I happens both when I use Firefox normally (with a few addons installed) and when I use the "safe mode". Does this really mean that the public key pinning doesn't work for addons.mozilla.org? If yes, what can I do against this? Thanks already for your answer!