Fix from empty attributes

Author: tvdijen

lib/Auth/Process/AttributeAddFromLDAP.php

@@ -106,7 +106,7 @@ public function process(array &$request): void
         foreach ($attributes as $attr => $val) {
             $arrSearch[] = '%' . $attr . '%';
 
-            if (strlen($val[0]) > 0) {
+            if (is_array($val) && count($val) > 0 && strlen($val[0]) > 0) {
                 $arrReplace[] = Ldap::escapeFilterValue($val[0]);
             } else {
                 $arrReplace[] = '';