Correct a 4.1.1 release notes typo

(cherry picked from commit d5cdcd9)

Author: michaelklishin

release-notes/4.1.1.md

@@ -117,7 +117,7 @@ Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://
 
    GitHub issue: [#13975](https://github.com/rabbitmq/rabbitmq-server/pull/13975)
 
- * `GET /api/health/checks/ready-to-serve-clients` is a new health check
+ * `GET /api/health/checks/below-node-connection-limit` is a new health check
    that responds a 200 OK if the target node has fewer connections to the AMQP
    and AMQPS ports than the configured maximum.