BTW, here is part of the akismet.php module code, including line 117:
115 add_filter( 'wpcf7_display_message', 'wpcf7_akismet_display_message', 10, 2 );
116
117 function wpcf7_akismet_display_message( $message, $status ) {
118 if ( 'spam' == $status && empty( $message ) )
119 $message = wpcf7_get_message( 'akismet_says_spam' );
120
121 return $message;