minor #966 Update form.rst (ruslan-polutsygan)

This PR was merged into the 1.2 branch.

Discussion
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Update form.rst

Before - http://i.imgur.com/Eu2JUvq.png
After - http://i.imgur.com/1d0CIAs.png

Must be the tiniest pull request ever :)

Commits
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cdc9ad6a Update form.rst

doc/providers/form.rst

@@ -58,7 +58,7 @@ Registering
         }
 
     If you are going to use the validation extension with forms, you must also
-    add a dependency to the ``symfony/config`` and ```symfony/translation``
+    add a dependency to the ``symfony/config`` and ``symfony/translation``
     components:
 
     .. code-block:: json