Author Tools option in instructor's user menu is an absolute URL to production

The Author Tools menu option in the instructor's user menu which displays on the course home page (ns/course/index) is a URL that leads to production (https://author.runestone.academy/author) instead of a relative URL. This displays an error when clicked in localhost or self-hosted installs.

Steps to Reproduce:

1. Log in as an instructor.
2. After logging in as an instructor with an existing course: Ensure you have an active course available.
3. Click the User Menu from navbar and select Course Home.
4. Once the Course Home page loads, locate and click the blue user icon on the right side of the screen.
5. From the dropdown, select Author Tools.

Expected : The Author Tools page should load successfully, as the user is logged in.

Actual Behavior:
Clicking Author Tools results in the following error message:

{ "detail": "You need to be Logged in to access this resource" }

Please change this to a relative URL so that it works in any environment.

Start at ns/course/index and inspect the Author Tools menu option and its URL. Change the production URL to a relative URL, then verify the link works from localhost or a self-hosted install without the login error.