minor #7917 Updated code example for LDAP integration (pmlt)

This PR was squashed before being merged into the 3.2 branch (closes #7917).

Discussion
----------

Updated code example for LDAP integration

The LdapClient class mentioned in the code example has been deprecated.
The update example, uses the Ldap class directly, as is recommended in
the deprecation notice.

Commits
-------

91e3e7d Updated code example for LDAP integration

Author: xabbuh

security/ldap.rst

@@ -49,8 +49,8 @@ The providers are configured to use a default service named ``ldap``,
 but you can override this setting in the security component's
 configuration.
 
-An LDAP client can be simply configured, using the following service
-definition:
+An LDAP client can be simply configured using the built-in ``ldap`` PHP
+extension with the following service definition:
 
 .. configuration-block::
 
@@ -59,13 +59,17 @@ definition:
         # app/config/services.yml
         services:
             ldap:
-                class: Symfony\Component\Ldap\LdapClient
+                class: Symfony\Component\Ldap\Ldap
+                arguments: ['@ext_ldap_adapter']
+            ext_ldap_adapter:
+                class: Symfony\Component\Ldap\Adapter\ExtLdap\Adapter
                 arguments:
-                    - my-server   # host
-                    - 389         # port
-                    - 3           # version
-                    - false       # SSL
-                    - true        # TLS
+                    -   host: my-server
+                        port: 389
+                        encryption: tls
+                        options:
+                            protocol_version: 3
+                            referrals: false
 
     .. code-block:: xml
 
@@ -76,31 +80,43 @@ definition:
             xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
 
             <services>
-                <service id="ldap" class="Symfony\Component\Ldap\LdapClient">
-                    <argument>my-server</argument>
-                    <argument>389</argument>
-                    <argument>3</argument>
-                    <argument>false</argument>
-                    <argument>true</argument>
+                <service id="ldap" class="Symfony\Component\Ldap\Ldap">
+                    <argument type="service" id="ext_ldap_adapter" />
+                </service>
+                <service id="ext_ldap_adapter" class="Symfony\Component\Ldap\Adapter\ExtLdap\Adapter">
+                    <argument type="collection">
+                        <argument key="host">my-server</argument>
+                        <argument key="port">389</argument>
+                        <argument key="encryption">tls</argument>
+                        <argument key="options" type="collection">
+                            <argument key="protocol_version">3</argument>
+                            <argument key="referrals">false</argument>
+                        </argument>
+                    </argument>
                 </service>
             </services>
         </container>
 
     .. code-block:: php
 
         // app/config/services.php
-        use Symfony\Component\Ldap\LdapClient;
+        use Symfony\Component\Ldap\Ldap;
+        use Symfony\Component\Ldap\Adapter\ExtLdap\Adapter;
         use Symfony\Component\DependencyInjection\Definition;
 
+        $container->register('ldap', Ldap::class)
+            ->addArgument(new Reference('ext_ldap_adapter'));
+
         $container
-            ->setDefinition('ldap', new Definition(LdapClient::class, array(
-                'my-server',
-                389,
-                3,
-                false,
-                true,
-
-            ));
+            ->setDefinition('ext_ldap_adapter', new Definition(Adapter::class, array(
+                'host' => 'my-server',
+                'port' => 389,
+                'encryption' => 'tls',
+                'options' => array(
+                    'protocol_version' => 3,
+                    'referrals' => false
+                )
+            )));
 
 Fetching Users Using the LDAP User Provider
 -------------------------------------------