fix listing user on 8.2.5

Author: c12simple

core/src/core/src/pydio/Core/Model/FilteredUsersList.php

@@ -379,8 +379,10 @@ public function load($filterValue, $allowCreation = true, $searchQuery = '', $gr
             $searchLimit = min($end - $offset, $this->getConf('USERS_LIST_COMPLETE_LIMIT'));
         }
         $baseGroup      = $this->computeBaseGroup($groupPathFilter, $searchQuery);
-        $baseGroup = rtrim($baseGroup, '/');
-        
+        if ($baseGroup != '/'){
+            $baseGroup = rtrim($baseGroup, '/');
+        }
+
         if(!empty($searchQuery)) {
             $regexp = '^'.$searchQuery;
             $pregexp = '/^'.preg_quote($searchQuery).'/i';