minor symfony#8737 Fixed some typos (javiereguiluz)

This PR was submitted for the 3.3 branch but it was merged into the 2.8 branch instead (closes symfony#8737).

Discussion
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Fixed some typos

Spotted while updating docs to Symfony 4.

Commits
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349038f Fixed some typos

Author: xabbuh

security/voters.rst

@@ -197,7 +197,7 @@ To recap, here's what's expected from the two abstract methods:
     object). Your job is to determine if your voter should vote on the attribute/subject
     combination. If you return true, ``voteOnAttribute()`` will be called. Otherwise,
     your voter is done: some other voter should process this. In this example, you
-    return ``true`` if the attribue is ``view`` or ``edit`` and if the object is
+    return ``true`` if the attribute is ``view`` or ``edit`` and if the object is
     a ``Post`` instance.
 
 ``voteOnAttribute($attribute, $subject, TokenInterface $token)``