Update NG-UI Dockerfile to force uncaching of deb package

Change-Id: Idebac79741dc60563ab234eb654b823c6d1bf120
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

docker/NG-UI/Dockerfile

@@ -38,6 +38,7 @@ RUN curl -s https://deb.nodesource.com/gpgkey/nodesource.gpg.key | apt-key add -
     DEBIAN_FRONTEND=noninteractive apt-get update && \
     DEBIAN_FRONTEND=noninteractive apt-get install -y nodejs
 
+ARG CACHE_DATE=not_a_date
 ARG OSM_NGUI_URL
 
 RUN curl $OSM_NGUI_URL -o osm_ngui.deb