Fix bug 1746 to allow installation without docker proxy

Change-Id: Ie840cbe538a33c5240dc0edf604477dbdfe5ac98
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

installers/full_install_osm.sh

@@ -657,7 +657,11 @@ function install_osm() {
 
     track prereqok
 
-    [ -n "$INSTALL_NODOCKER" ] || $OSM_DEVOPS/installers/install_docker_ce.sh -p $DOCKER_PROXY_URL -D $OSM_DEVOPS $DEBUG_INSTALL
+    if [ ! -n "$INSTALL_NODOCKER" ]; then
+        DOCKER_CE_OPTS="-D ${OSM_DEVOPS} ${DEBUG_INSTALL}"
+        [ -n "${DOCKER_PROXY_URL}" ] && DOCKER_CE_OPTS="${DOCKER_CE_OPTS} -p ${DOCKER_PROXY_URL}"
+        $OSM_DEVOPS/installers/install_docker_ce.sh ${DOCKER_CE_OPTS}
+    fi
 
     track docker_ce