network/net-lib.sh: correctly set mac address for ip=...:<mtu>:<mac>

if ip=...:<mtu>:<mac> was specified, macadress was not set

(cherry picked from commit efbc47b8e4)

modules.d/40network/net-lib.sh

@@ -421,6 +421,9 @@ ip_to_var() {
                     ;;
                 [0-9]*)
                     mtu="$8"
+                    if [ -n "${9}" -a -n "${10}" -a -n "${11}" -a -n "${12}" -a -n "${13}" -a -n "${14}" ]; then
+                        macaddr="${9}:${10}:${11}:${12}:${13}:${14}"
+                    fi
                     ;;
                 *)
                     if [ -n "${9}" -a -n "${10}" -a -n "${11}" -a -n "${12}" -a -n "${13}" -a -n "${14}" ]; then