minor #8353 Update service_container.rst (atailouloute)

This PR was merged into the 3.3 branch.

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Update service_container.rst

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d557acd Update service_container.rst

Author: xabbuh

service_container.rst

@@ -991,7 +991,7 @@ admin email. In this case, each needs to have a unique service id:
                     <argument>contact@example.com</argument>
                 </service>
 
-                <alias id="AppBundle\Updates\SiteUpdateManager" service="site_update_manager.superadmin">
+                <alias id="AppBundle\Updates\SiteUpdateManager" service="site_update_manager.superadmin" />
             </services>
         </container>