[Dovecot] Reporting NFS quotas via IMAP

[Edgar Fuß]

> Try with manual IMAP commands instead:
Yes, sorry, I should have checked that before.

> Does it return correct output?
Yes.

> IIRC some clients (maybe Apple Mail?) had problems listing quota if  
> quota root was empty.
Hmpf. So I was just using a defective client to test my presumably  
defective confuration.

> If that's the case, change it (quota = maildir:userquota).
fs:user did the trick. Thanks.

Would this catch be worth being documented in the WIKI?