Fix REGISTER_BASE_URL variable name
The REGISTER_BASE_URL variable was misspelled in the documentation, which was causing locally-executed tests to fail when copy/pasted.
Starting on April 8th, The Open Group will require Two Factor Authentication for all GitLab users. For instructions on setting up 2FA, see the Knowledge Article or GitLab Documentation. Note in particular that any HTTPS clones will require the use of a Personal Access Token (rather than a user’s password) once 2FA is enabled.
The REGISTER_BASE_URL variable was misspelled in the documentation, which was causing locally-executed tests to fail when copy/pasted.