Fix copyright hint for wordlists.

COPYRIGHT

 The diceware idea Copyright(C) 1995-2015, Arnold G. Reinhold,
 Cambridge, Massachusetts USA.
 
-The English Diceware Wordlist used with this programme (file
-``wordlists/wordlist_en.txt``) is licensed by Arnold G. Reinhold under
-the `Creative Commons CC-BY 3.0` (see
-http://creativecommons.org/licenses/by/3.0/) license.
+The English Diceware Wordlists used with this programme (files
+``wordlists/wordlist_en_orig.asc``, ``wordlists/wordlist_en_8k.txt``)
+are licensed by Arnold G. Reinhold under the `Creative Commons CC-BY
+3.0` (see http://creativecommons.org/licenses/by/3.0/) license.
 
 "Diceware" is a trademark of A G Reinhold.