Using GitLab as Terraform backend won't work if the Project Name contains a dot

When using a Project with a dot in its Project Path (i.e. "gitlab.com") the locking endpoint returns a 404

$ terraform plan  

Error: Error locking state: Error acquiring the state lock: Unexpected HTTP response code 404

When using a Project without a dot in its name it works perfectly fine.

Edited by Jean-Philippe Quéméner