Yarn audit does not work with an external repository

Do you want to request a feature or report a bug? Bug

What is the current behavior?

When running yarn audit with the --registry flag, it uses the main yarn repo anyway.

If the current behavior is a bug, please provide the steps to reproduce.

Execute yarn audit --registry https://registry.npmjs.org/

What is the expected behavior?

Audit calls are made to the defined registry. This is especially important for everyone with third party repo's where the outside world it blocked on CI agents. Or if you're using some kind of proxy.

Please mention your node.js, yarn and operating system version.

Mac Os Mojave Yarn 1.13.0 Node 10.15.1