request: add IP address to a log message to allow blocking

[IMAP List Administration]

Hello,

I'm seeing a lot of messages like this:

    fatal: Read from socket failed: Connection reset by peer [preauth]

I presume they are the result of someone trying a brute-force attack of some
kind, and would like to ban the attacker, but cannot, because the IP address is
missing.

If you haven't already, an you please add the IP address to this message, and
any similar messages?  I'm using version 6.7p1.

thanks,
Rob