Has this long-running series finally lost its edge, and its appetite to approach third-rail subjects? Uh, no. Not even close. Last week, in its Season 22 premiere, South Park did a show about multiple school shootings, including at South Park. And tonight, in an episode called “A Boy and a Priest,” South Park has Butters developing a relationship with his parish priest that leads to Catholic Church leaders being notified, and called in. And this is only week two of the new season…