message: contrib/federation-experiment: fix friendly message
diff: @@ -199,4 +199,4 @@ $KUBECTL apply -f clusters --validate=false
  printf "Run the following commands in the JavaScript console in the Tectonic Console to enable the cluster picker:\n"
  printf "localStorage.setItem('federation-apiserver-token', '%s');\n" "$FEDERATION_TOKEN"
  -printf "localStorage.setItem('federation-apiserver-url', '%s');\n" "$HOST_CONSOLE_URL"
  +printf "localStorage.setItem('federation-apiserver-url', '%s/federation');\n" "$HOST_CONSOLE_URL"
  