Queue module is not usable on Windows

[foxcpp]

Method updateMetadataOnDisk tries to move metadata file while it is open. Also, os.Rename is used to replace previous file (if any).

[foxcpp]

I believe the referenced commit fixes it. Could anyone confirm?

[rawtaz]

FWIW I was the one who initially reported the problem, and today I ran the as-of-writing-this master@5eec45e and am no longer seeing this issue. I've only done a couple of test mails though, but I see maddy accepting them and then retrying the queue as well when they can't be delivered due to other network problems. Seems you can close this.