minor #12990 [Messenger] Updated link (Nyholm)

This PR was submitted for the master branch but it was merged into the 4.3 branch instead (closes #12990).

Discussion
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[Messenger] Updated link

The link https://github.com/php-enqueue/messenger-adapter redirects to https://github.com/sroze/messenger-enqueue-transport

The `php-enqueue` did not want to maintain that package.

Commits
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823074b Updated link

Author: javiereguiluz

messenger.rst

@@ -1482,6 +1482,6 @@ Learn more
 
     /messenger/*
 
-.. _`Enqueue's transport`: https://github.com/php-enqueue/messenger-adapter
+.. _`Enqueue's transport`: https://github.com/sroze/messenger-enqueue-transport
 .. _`streams`: https://redis.io/topics/streams-intro
 .. _`Supervisor docs`: http://supervisord.org/