Fix bug 1727: fix metallb ip range

Metallb was complaining when indicating an IP range of a single IP.
This commit changes the IP range "<IP>-<IP>" to CIDR format: "<IP>/32"

Change-Id: If879fab2b272927a6a8ffda00f9c49f218224ac0
Signed-off-by: David Garcia <david.garcia@canonical.com>

installers/full_install_osm.sh

@@ -851,7 +851,7 @@ function install_k8s_storageclass() {
 }
 
 function install_k8s_metallb() {
-    METALLB_IP_RANGE=$DEFAULT_IP-$DEFAULT_IP
+    METALLB_IP_RANGE=$DEFAULT_IP/32
     kubectl apply -f ${OSM_DEVOPS}/installers/k8s/metallb/metallb.yaml \
     || FATAL "Cannot install MetalLB"
     echo "apiVersion: v1
@@ -871,7 +871,7 @@ data:
 
 #installs metallb from helm
 function install_helm_metallb() {
-    METALLB_IP_RANGE=$DEFAULT_IP-$DEFAULT_IP
+    METALLB_IP_RANGE=$DEFAULT_IP/32
     echo "configInline:
   address-pools:
    - name: default