[Dovecot] tb-negative-fetch workaround

Hi,

I notice in the Changelog that the tb-negative-fetch workaround shouldn't be needed any longer. We have a user running Thunderbird 1.5.0.8 that is experiencing the same problem described in https://bugzilla.mozilla.org/show_bug.cgi?id=263904

The current command did not succeed. the mail server responded: error in imap command uid: invalid body[..] parameter. Missing '>' in '<12288.-7215>'

Any ideas?

Thanks!