The NCAA will go it alone defending against a proposed class-action lawsuit alleging football players at the University of Florida were not adequately protected from the effects of repeated concussions.In a written opinion this week, U.S. District Judge John Z. Lee dismissed the Southeastern Conference — of which Florida is a member school — as a defendant in the suit.Lee did not rule on the merits of the claims against the SEC, which included negligence, fraudulent concealment and breach of contract …