IBX-1467: Fixed OOM regression during Subtree copying (#3128)

Author: barw4

eZ/Publish/Core/Persistence/Legacy/Content/UrlAlias/Handler.php

@@ -983,14 +983,11 @@ protected function copySubtree($actionMap, $oldParentAliasId, $newParentAliasId,
 
             $alreadyGeneratedAliases[] = $identifier;
 
-            $alreadyGeneratedAliases = array_merge(
-                $alreadyGeneratedAliases,
-                $this->copySubtree(
-                    $actionMap,
-                    $oldParentAliasId,
-                    $row['id'],
-                    $alreadyGeneratedAliases
-                )
+            $alreadyGeneratedAliases = $this->copySubtree(
+                $actionMap,
+                $oldParentAliasId,
+                $row['id'],
+                $alreadyGeneratedAliases
             );
         }