Actor Henry Winkler, still best known as the Fonz on “Happy Days,” lost one of his two Emmy nominations on Friday, after the Academy of Television Arts & Sciences discovered that the appearance for which he was nominated (on “Battery Park”) did not air during the eligible period. He was replaced in the category of outstanding comedy guest actor by William H. Macy, for his guest appearances on “Sports Night.” Still, Winkler, 54, remains nominated in the drama guest actor category for his role on “The Practice.”