Fix CLAMP-TIMEOUT for NULL timeouts.
Fix CLAMP-TIMEOUT for NULL timeouts.

lispnik/iolib,vsedach/iolib-simple-mux,deadtrickster/iolib,dkochmanski/iolib,dkochmanski/iolib,sionescu/iolib,dkochmanski/iolib,lispnik/iolib,attila-lendvai/iolib,tiago4orion/iolib,shamazmazum/iolib,attila-lendvai/iolib,shamazmazum/iolib,deadtrickster/iolib,attila-lendvai/iolib,sionescu/iolib,sionescu/iolib,shamazmazum/iolib,vsedach/iolib-simple-mux,tiago4orion/iolib,lispnik/iolib,deadtrickster/iolib,tiago4orion/iolib