Fix warning when an attribute is empty (#16)

* fix warning when an attribute is empty

* check if attribute value is an array

Co-authored-by: brousekp <58169464+brousekp@users.noreply.github.com>

Author: tvdijen

lib/Auth/Process/AttributeAddFromLDAP.php

@@ -95,7 +95,7 @@ public function process(array &$state): void
         foreach ($attributes as $attr => $val) {
             $arrSearch[] = '%' . $attr . '%';
 
-            if (strlen($val[0]) > 0) {
+            if (is_array($val) && count($val) > 0 && strlen($val[0]) > 0) {
                 $arrReplace[] = $this->connector->escapeFilterValue($val[0], true);
             } else {
                 $arrReplace[] = '';