minor #15444 [Routing] Fix typo (praftr)

This PR was submitted for the 5.3 branch but it was merged into the 4.4 branch instead.

Discussion
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[Routing] Fix typo

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Commits
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7f04f37 Update routing.rst

Author: wouterj

routing.rst

@@ -1892,7 +1892,7 @@ use the ``generateUrl()`` helper::
 
     While objects are converted to string when used as placeholders, they are not
     converted when used as extra parameters. So, if you're passing an object (e.g. an Uuid)
-    as value of an extra parameter, you need to explictly convert it to a string::
+    as value of an extra parameter, you need to explicitly convert it to a string::
 
         $this->generateUrl('blog', ['uuid' => (string) $entity->getUuid()]);