Nighwatch - multiple basic auth

I have situation like this: I'm logging to stage http server which is secured by basic auth. I'm running my test with url combined with basic auth credentials url("http://ift.tt/2bV0DcD")

Then I'm going to website login page and backend server switches protocol to https, showing new basic auth window.

Any ideas how to handle it in Nightwatch? How to handle multiple basic auth alerts?