A class-action conspiracy lawsuit against State Farm Insurance Co. preliminarily reached a $250 million settlement on Tuesday in East St. Louis federal court.The plaintiffs filed the suit seeking nearly $10 billion from State Farm in a trial that was scheduled to begin today and run for six weeks.The class alleged in the suit that the Bloomington-based insurance giant secretly funneled money to the campaign committee for Lloyd A. Karmeier, now the chief justice of the Illinois Supreme Court, while he was a candidate for …