Disorderly conduct is either a summary offense or a third-degree misdemeanor. If yours was a summary, entirely handled in front of a district judge, you do not have to report it in any event. If the application says to list only felonies, you still do not need to report it. If you are required to report any offenses, given the circumstances I would omit this and, if you are questioned about it, would respond to your questioner with the same information that you have given here. That should be sufficient for the Commonwealth.
It is very fact specific. If it says specifically "convicted," a case being dismissed is not a conviction. However, it is very fact specific and someone should look at it for you and make sure about the language used and the disposition of your case.