New "test" domain?

Upon updating from Virtualmin Professional 3.30 to 3.31, I now see a "test" domain at the top of the dropdown list in the Virtualmin Framed Theme when logged in as root (Master admin). I did not create this domain, and it doesn't appear anywhere in the filesystem, as far as I can tell.

Is this some debugging feature that was left in the 3.31 release by accident, or is there something weird happening on my server?

Status: 
Closed (fixed)