bug #6001 Fix class name (BlueM)

This PR was submitted for the 3.0 branch but it was merged into the 2.7 branch instead (closes #6001).

Discussion
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Fix class name

Commits
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b0772c0 Fix class name

Author: wouterj

components/dependency_injection/factories.rst

@@ -34,7 +34,7 @@ object::
 
 To make the ``NewsletterManager`` object available as a service, you can
 configure the service container to use the
-``NewsletterFactory::createNewsletterManager()`` factory method:
+``NewsletterManagerFactory::createNewsletterManager()`` factory method:
 
 .. configuration-block::