"ASHTON Kutcher and Demi Moore should run out and get hepatitis-A shots ASAP. So should Madonna, Lucy Liu, Salma Hayek, Kate Hudson and Bruce Willis." Thus advised the public health experts of Page Six magazine after it was discovered that a worker at Armin Amiri's club, Socialista, had tested positive for Hepatitis. It was a sweet little punchline for those who find it amusing to have something on an exclusive downtown club. But Mr. Amiri's dream of creating a place where Manhattan celebrities regularly go to hit the booze actually came true, even if those boldfaced names appeared in the context of a health advisory.