Update exim

When using Dovecot authentication for Exim, which is relatively common, the current regex for catching authentication failures needs a small tweak. The current plain|login options are too limiting and will only work in the cases when only the Exim's rudimentary built-in authentication is used. There can be not only the dovecot_login shown in this log example, but also dovecot_plain, ntlm, cram, cyrus, md5, and plenty of others. In fact many admins may opt for their own authentication labels, when setting up Exim. For this reason the regex should catch any label. I suggest modifying the regex in the following way:

<pre>^%(pid)s \w+ authenticator failed for (\S+ )?\(\S+\) \[<HOST>\]: 535 Incorrect authentication data( \(set_id=.*\)|: \d+ Time\(s\))?\s*$</pre>