From NBC The world’s largest online poker website is appealing a judge’s ruling that cost it the right to buy an Atlantic City casino. The PokerStars website’s parent company, The Rational Group, had a deal to buy The Atlantic Club Casino Hotel – and had already paid $11 million of that to keep it afloat during the winter. But a judge last month let the Atlantic Club out of that deal, ruling that a deadline for Rational to obtain preliminary approval from state authorities to own a casino had passed. The Rational Group appealed that ruling this week. “This is…