do not accept 425 as `file should not exist`

[individual-it]

@Then as :user :entry :path should not exist will accept any 4xx return code as valid see

opencloud/tests/acceptance/bootstrap/WebDav.php

Line 1267 in fb8af22

if ($statusCode < 400 || $statusCode > 499) {

I think 425 should not be accepted, but in that case it should retry