minor #16182 [Messenger] Fix example config (shafan)

This PR was merged into the 5.4 branch.

Discussion
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[Messenger] Fix example config

The reset_on_message config is in messenger and not in async.

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Commits
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ccc04fe Fix exemple config

Author: javiereguiluz

messenger.rst

@@ -719,10 +719,11 @@ reset the service container between two messages:
         # config/packages/messenger.yaml
         framework:
             messenger:
+                reset_on_message: true
                 transports:
                     async:
                         dsn: '%env(MESSENGER_TRANSPORT_DSN)%'
-                        reset_on_message: true
+                        
 
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