Allow unauthenticated access to the `GET /projects/:id/repository/branches` endpoint

Summary

This is reported fixed in #4269 (closed) but it is not yet.

Could not fetch https://gitlab.com/api/v3/projects/drutopia%2Fdrutopia%5Fsite/repository/branches, enter your gitlab.com credentials to access private repos A token will be created and stored in "/home/vagrant/.composer/auth.json", your password will never be stored

But https://gitlab.com/drutopia/drutopia_site is a public project. Please fix this on gitlab.com; it's really hurting our efforts to make it easy to get involved in our community project.

Steps to reproduce

Add a public gitlab project to a composer.json file.

Run composer update

What is the current bug behavior?

Halting the install/update and showing the message: "Could not fetch https://gitlab.com/api/v3/projects/[project name]/repository/branches, enter your gitlab.com credentials to access private repos"

What is the expected correct behavior?

The public repository is successfully cloned.

Output of checks

This bug happens on GitLab.com

Possible fixes

Make sure https://gitlab.com/gitlab-org/gitlab-ce/issues/4269 works as described and is deployed to Gitlab.com

Thank you.