minor #16494 Fix: Remove space (OskarStark)

This PR was merged into the 5.4 branch.

Discussion
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Fix: Remove space

Commits
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10ad5ac Fix: Remove space

Author: javiereguiluz

messenger.rst

@@ -546,8 +546,8 @@ different messages to them. For example:
                             queue_name: low
 
                 routing:
-                    'App\Message\SmsNotification':  async_priority_low
-                    'App\Message\NewUserWelcomeEmail':  async_priority_high
+                    'App\Message\SmsNotification': async_priority_low
+                    'App\Message\NewUserWelcomeEmail': async_priority_high
 
     .. code-block:: xml