[Dovecot] null errors from 2.0.beta5

[Mike Abbott]

When my dovecot-2.0.beta5 auth module logs a 552-byte debug message, the message is split into two lines and also a null error message:
Wed Jun  9 23:44:29 gromit dovecot[58892]: auth: Error: 

I think this has to do with the use of PIPE_BUF (512) sized buffers in the logging code, and the !line_is_ok() case in i_failure_parse_line().

Could you please remove the null error message?  Just a nuisance, nothing serious.  Thanks.