Add a disclaimer in the about page to make it clearer that I'm not th…

…e one responsible for the books made available (I got two mails from book authors some weeks ago).

about.html

@@ -14,6 +14,8 @@ <h2>Contact</h2>
 <p>For more info please visit <a href="http://blog.slucas.fr/en/oss/calibre-opds-php-server">COPS Home Page</a></p>
 
 <p>You can also check <a href="http://www.mobileread.com/forums/showthread.php?t=170903">COPS's topic on MobileRead forum</a>.</p>
+
+<p>DISCLAIMER : COPS is an open source software free to install everywhere. So if you have questions about any books available with any installation of COPS, please ask the owner of the website and not COPS's maintainer.</p>
 <h2>Thanks</h2>
 <p>Thanks a lot to Kovid Goyal for <a href="http://calibre-ebook.com">Calibre</a>.</p>