We have an installation of phpMyAdmin that uses the cookie authentication mode. We do not have mcrypt installed due to problems we encountered trying to get mcrypt included in our php installation. Since we are aware that mcrypt is not installed, we would like to disable the warning message (Cannot load mcrypt extension. Please check your PHP configuration) so that it does not confuse our users. To do this, I commented out line 25 (define('PMA_WARN_FOR_MCRYPT', 0);) in libraries/auth/cookie.auth.lib.php. It would be nice if phpMyAdmin provided a configuration variable that would allow a user to disable that particular warning.
Implemented in SVN, thanks for suggestion.