noted in the Coding Notes is replacing this.

Removed the files favicon.ico and robots.txt from conf-custom directory as they are already present in conf directory. The conf-custom directory is only for local overrides of files from conf directory, so conf-custom must stay empty in the source tree to allow administrators to override files on their servers.

the server logs.  The load and traffic are small but the logs are insanely 
stupid.

can now be set in the localconfig.

stop the 404s from new browsers that check.

default favicon.ico which is blank, a simple 
.htaccess, and a simple robots.txt.  This will 
also reduce 404s on the whole server

http://bugtracker.ispconfig.org/index.php?do=details&task_id=1601&project=3

Thanks Ben Lake