imap errors show as "unknown error code" rather than strings

[OpenMacNews]

imap related error messages in cyrus-imap are printing out as "unknown error code" #s, rather
than the relevant/assigned strings.

e.g. from imtest,

	S: C01 OK Unknown Error Code: -1904809420

cref: https://bugzilla.andrew.cmu.edu/show_bug.cgi?id=2721

fwiw, i've built imap latest HEAD on both OSX 10.3.9 & 10.4.3.

thanks,

richard