LdapResourceForm: Remove hostname validator

It's now done automatically by the connection itself.

refs #3639

application/forms/Config/Resource/LdapResourceForm.php

@@ -48,38 +48,7 @@ public function createElements(array $formData)
                     'The hostname or address of the LDAP server to use for authentication.'
                     . ' You can also provide multiple hosts separated by a space'
                 ),
-                'value'         => 'localhost',
-                'validators'    => array(
-                    array(
-                        'Callback',
-                        false,
-                        array(
-                            'callback'  => function ($v) {
-                                $withoutScheme = $withScheme = false;
-                                foreach (explode(' ', $v) as $uri) {
-                                    if (preg_match('~^(?<!://)[^:]+:\d+$~', $uri)) {
-                                        return false;
-                                    }
-
-                                    $url = Url::fromPath($uri);
-                                    if ($url->getScheme()) {
-                                        $withScheme = true;
-                                    } else {
-                                        $withoutScheme = true;
-                                    }
-                                }
-
-                                return $withScheme ^ $withoutScheme;
-                            },
-                            'messages'  => array(
-                                'callbackValue' => $this->translate(
-                                    'A protocol scheme such as ldap:// or ldaps:// is mandatory for URIs with a given'
-                                    . ' port and for all other URIs as well once a scheme is given for a single one.'
-                                )
-                            )
-                        )
-                    )
-                )
+                'value'         => 'localhost'
             )
         );
         $this->addElement(