minor #11287 fix use statement (OskarStark)

This PR was merged into the 3.4 branch.

Discussion
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fix use statement

use lowercase "as"

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Commits
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18851fc fix use statement

Author: javiereguiluz

doctrine/resolve_target_entity.rst

@@ -63,7 +63,7 @@ An Invoice entity::
 
     namespace Acme\InvoiceBundle\Entity;
 
-    use Doctrine\ORM\Mapping AS ORM;
+    use Doctrine\ORM\Mapping as ORM;
     use Acme\InvoiceBundle\Model\InvoiceSubjectInterface;
 
     /**