correctly propagate the return value of ldap_set_option

otherwise LDAP_OPT_REFERRALS won't be set to 0 and in turn
active directory paging will stop working
(Operations error on ldap_control_paged_result_response)

apps/user_ldap/lib/ldap.php

@@ -91,7 +91,7 @@ class LDAP implements ILDAPWrapper {
 	}
 
 	public function setOption($link, $option, $value) {
-		$this->invokeLDAPMethod('set_option', $link, $option, $value);
+		return $this->invokeLDAPMethod('set_option', $link, $option, $value);
 	}
 
 	public function sort($link, $result, $sortfilter) {