Encode current page in anon-stats query string

[vbrown608]

Matomo tries to use the referrer header to figure out which page a user visited, but this is unreliable. We can encode the current page directly in the query string that goes to anon-stats.

[mfb]

well they are two separate things, urlref and url

[vbrown608]

I mean the referrer to anon-stats.eff.org (eg the page w/in certbot.eff.org on which they loaded the tracker), not urlref, which I understand to be the referrer to certbot.eff.org.

[mfb]

oh right. yes we should always send the url param as a rule.