Give a unique port range for each validator node (#5397)

automerge

multinode-demo/bootstrap-leader.sh

@@ -23,6 +23,9 @@ while [[ -n $1 ]]; do
     elif [[ $1 = --gossip-port ]]; then
       args+=("$1" "$2")
       shift 2
+    elif [[ $1 = --dynamic-port-range ]]; then
+      args+=("$1" "$2")
+      shift 2
     else
       echo "Unknown argument: $1"
       $program --help