Change log level in mailheader.js (#2299)
Change log level in mailheader.js (#2299)

An unusual header is not an error condition. Changed log severity to notice.
msimerson/Haraka,smfreegard/Haraka,msimerson/Haraka,msimerson/Haraka,smfreegard/Haraka,smfreegard/Haraka,haraka/Haraka,haraka/Haraka,haraka/Haraka,smfreegard/Haraka,msimerson/Haraka,haraka/Haraka