It's not.

The interview will more than likely start with some kind of "Tell me about yourself" question. Another path to consider would be to complete that brief portion, then segway into your (very minor) app issue in an "I'd also like to mention" manner. Either way, you know, and they know, that your app changed, and it should be addressed within minutes of the interview starting. Set the tone that you do not lie, cheat or steal.