minor symfony#7309 Remove duplicate use operator (ThomasLomas)

This PR was submitted for the 3.2 branch but it was merged into the 2.8 branch instead (closes symfony#7309).

Discussion
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Remove duplicate use operator

Commits
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6426109 Remove duplicate use operator

Author: xabbuh

forms.rst

@@ -660,7 +660,6 @@ the choice is ultimately up to you.
 
         use AppBundle\Entity\Task;
         use Symfony\Component\OptionsResolver\OptionsResolver;
-        use AppBundle\Entity\Task;
 
         // ...
         public function configureOptions(OptionsResolver $resolver)