An ex-con who vanished after being released without bail on gun charges by a soft-on-crime judge was captured by federal agents in Puerto Rico, a source said Wednesday. Frankie Centeno, who allegedly ignored an order to get fitted with an ankle bracelet following his release, was nabbed on the Caribbean island on Tuesday night, the source said. It’s unclear when he’ll be brought back to New York to face prosecution for allegedly being a felon in possession of a firearm. Centeno, who has four gun-possession convictions that date to 2003, was arrested early March 27 inside a Bronx restaurant and...