Just tried clicking that link, and got a huge pop up refusing me access to the site, and accusing me from being from a site called Hacker News (???).
According to the text in the screenshot you've posted, there is no referrer header, so perhaps you're using some privacy extension that strips referrers.
"contributor license agreement" is such a broad term, a CLA is not bad in all cases. There are plenty of CLAs that are not about one-way proprietarization of software. Examples of OK CLAs are "You agree that you actually have the right to contribute code" or "If you don't specifically attach add a license header, the MIT license is being used".
Obviously companies like Canonical use the term CLA to make their practices look less shady that it actually is.
According to the text in the screenshot you've posted, there is no referrer header, so perhaps you're using some privacy extension that strips referrers.