title: Issue with AdLdap2 at Laravel 5.5
body: <p>I receiving an error when i am trying to use LDAP with Laravel 5.5</p>
  
  <pre><code>"Use of undefined constant LDAP_OPT_PROTOCOL_VERSION - assumed 'LDAP_OPT_PROTOCOL_VERSION'"
  </code></pre>
  
  <p>However, i have enabled the PHP extension of LDAP </p>
  
  <pre><code>$ php --ini |grep ldap
  
  /etc/php.d/ldap.ini,
  </code></pre>
  
  <p>and</p>
  
  <pre><code>$ cat /etc/php.d/ldap.ini
  ; Enable ldap extension module
  extension=ldap.so
  </code></pre>
  
  <p>and php information</p>
  
  <pre><code>$ php --info |grep ldap
  /etc/php.d/ldap.ini,
  Protocols =&gt; dict, file, ftp, ftps, gopher, http, https, imap, imaps, ldap, ldaps, pop3, pop3s, rtsp, scp, sftp, smtp, smtps, telnet, tftp
  ldap
  ldap.max_links =&gt; Unlimited =&gt; Unlimited
  </code></pre>
  
  <p>I am using </p>
  
  <pre><code>$ php -v
  PHP 7.1.10 (cli) (built: Sep 30 2017 10:30:04) ( NTS )
  Copyright (c) 1997-2017 The PHP Group
  Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
      with Zend OPcache v7.1.10, Copyright (c) 1999-2017, by Zend Technologies
  </code></pre>