Description of problem:
Unable to configure filesystem quotas in dovecot.

Version-Release number of selected component (if applicable):
dovecot-2.0.16-1.fc16.x86_64
dovecot-2.0.15-1.fc16.x86_64

How reproducible:
always

Steps to Reproduce:
1. configure filesystem quotas
2. nc localhost 143 # and type:
   1 login LOGIN PASSWORD
   1 GETQUOTAROOT "INBOX"

Actual results:
2 OK No quota.

Expected results:
* QUOTAROOT "INBOX" "User quota"
* QUOTA "User quota" (STORAGE 216 204800)
0 OK Getquotaroot completed.

Additional info:
Configuration:
plugin {
  quota = fs:User quota
}
protocol imap {
  mail_plugins = quota imap_quota
}

Maillog output:
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: Effective uid=1190, gid=1002, home=/home/sukromne/test.test
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: Quota root: name=User quota backend=fs args=
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: maildir++: root=/home/sukromne/test.test/Maildir, index=/var/spool/dovecot/test.test, control=/var/spool/dovecot/test.test, inbox=/home/sukromne/test.test/Maildir, alt=
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: fs quota add mailbox dir = /home/sukromne/test.test/Maildir
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: fs quota block device = /dev/mapper/vg_mail-home
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: fs quota mount point = /home
Nov 24 11:30:07 mail dovecot: imap(test.test): Debug: fs quota mount type = ext4
Nov 24 11:30:07 mail dovecot: imap(test.test): Disconnected: Logged out bytes=54/702