Delta Airlines acknowledged Wednesday it wronged a Marine veteran with prosthetics legs who said he was forced by a flight crew to move from a seat in the emergency exit row, setting off a lawsuit this week. The airline issued a mea culpa two days after Matias Ferreira, now a Suffolk County cop, accused the company in legal papers of discriminating against him before takeoff on a May flight from JFK Airport to Atlanta because he’s a double amputee. Delta said in a statement — also two days