minor symfony#6523 Fix snippet (ismailbaskin)

This PR was submitted for the 3.0 branch but it was merged into the 2.3 branch instead (closes symfony#6523).

Discussion
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Fix snippet

Semicolon removed

Commits
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3663208 Fix snippet

Author: xabbuh

components/dependency_injection/parentservices.rst

@@ -385,7 +385,7 @@ to the ``NewsletterManager`` class, the config would look like this:
 
         $mailManager = new Definition();
         $mailManager
-            ->setAbstract(true);
+            ->setAbstract(true)
             ->addMethodCall('setMailer', array(
                 new Reference('my_mailer'),
             ))