File downloaded logic

[lanruth]

Additional to #92

Using this script with proxy give some time access to site before cookie is outdated and script fails with error 403. With current script logic, image that was unable to download saves with name fpath.with_name(fpath.name + "_SKIPPED"). This works as expected only in scenarios when server return error 404, file not found. With 403 error empty file saved with '_SKIPPED' and won't be downloaded next time then script started.

In my case script must stop for 'cf_clearance' manually update