A high-ranking human rights worker with ties to the United Nations was nabbed at Kennedy Airport Tuesday with kiddie porn in his suitcase, officials said. Clarence Dias, 65, president of the International Center for Law in Development, whose offices are located at the UN, had the smut in his carry-on bag as he passed through security on his way to a flight bound for Bangkok, Queens District Attorney Richard Brown said. Transportation Security Administration officials doing a random bag check around 8:20a.m. allegedly found a DVD whose cover featured an apparently underage nude boy and an adult male in