At Mustang Harry’s, it’s all in the family. The longtime Midtown sports bar is celebrating its 30th anniversary — and owners Ian and Niall Conroy attribute the beloved watering hole’s longevity to their efforts to form a tight community of regulars. “We run it like a family-run restaurant: our patrons have been friends over the years, and the ones that come in for lunch come in every week, multiple times a week,” Ian, 63, told The Post ahead of the bar’s anniversary celebration kickoff on