Update an issue link in 3.12.1 release notes

Author: michaelklishin

release-notes/3.12.1.md

@@ -32,7 +32,7 @@ Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://
 
    Contributed by @gomoripeti (CloudAMQP).
 
-   GitHub issue: [#8458](https://github.com/rabbitmq/rabbitmq-server/pull/8458)
+   GitHub issue: [#8453](https://github.com/rabbitmq/rabbitmq-server/pull/8453)
 
 
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