hide backup compression select

app/UI/Backup/Forms/CreateForm.php

@@ -71,6 +71,7 @@ class CreateForm extends BaseForm implements ClientArea
             "zstd" => sl("lang")->abtr("ZSTD (fast and good)")
         ]);
         $field->setDefaultValue('zstd');
+        $field->addClass('hidden');
         $this->addField($field);
         //mode
         $field = new Select('mode');