GRAND CANYON NATIONAL PARK, Ariz.—A body found at the Grand Canyon is believed to be a Hungarian man who was reported missing in July, authorities said. The body believed to be Gabor Berczi-Tomcsanyi, 45, was found Monday about 430 feet below the rim at Yavapai Point, Grand Canyon National Park officials said Wednesday. Berczi-Tomcsanyi was…