Invalid syntax warning when LDAP Profile fields are empty

When user logins or updates Profile field which is optional and the field is empty in LDAP, you'll receive: "warning: ldap_mod_del () []: Modify: Invalid syntax in ldap_integration\ldap_integration\LDAPInterface.php on line 214" for each empty field.

Reported before in http://drupal.org/node/80204#comment-439397, but seems like everyone missed it.

This fixes the problem:

Line 214: modules/ldap_integration/ldap_integration/LDAPInterface.php
Change this

          ldap_mod_del($this->connection, $dn, array($key => $old_value));

To

        if ($old_value != null) {
          ldap_mod_del($this->connection, $dn, array($key => $old_value));
        }