New MailScanner Front-End v4.42

Changes:
– Added support for cPanel v11.38.1+ AppConfig addon registration

NOTE: In accordance with the new conventions for v11.38.1+ AppConfig the url to the msfe WHM plugin will change from /cgi/addon_mailscanner.cgi to /cgi/configserver/mailscanner.cgi. This will only happen with msfe v4.41+ and cPanel v11.38.1+. Older version of msfe will continue to use the old URL. This has no particular relevance to users accessing through WHM, but will affect direct URL access by users or third party applications. The URL to MailWatch will remain the same