If the URL to a private repo is not secure, then a whole bunch of people (including GitHub) have a big problem, and exposing jobmachine is the least of their worries ;-)
It's not a security problem, or else my comment would have been much more adamant about removing the link. It's mostly just reader confusion. Seeing the git clone url led me to believe the project was open sourced and was disappointed to find that not to be the case.