minor #11588 Update ldap.rst (kboumedal)

This PR was submitted for the 4.2 branch but it was merged into the 3.4 branch instead (closes #11588).

Discussion
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Update ldap.rst

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Commits
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233ff60 Update ldap.rst

Author: OskarStark

security/ldap.rst

@@ -102,7 +102,7 @@ An LDAP client can be simply configured using the built-in
         use Symfony\Component\Ldap\Ldap;
 
         $container->register(Ldap::class)
-            ->addArgument(new Reference(Adapter::class);
+            ->addArgument(new Reference(Adapter::class));
 
         $container
             ->register(Adapter::class)