Remove broken link in `plugin_list.ejs` (#3166)

website/themes/uppy/layout/partials/plugin_list.ejs

@@ -36,8 +36,7 @@
 <iframe scrolling="no" seamless="seamless" class="Disc" src="/disc.html"></iframe>
 <p>
   This graph is built with
-  <a href="https://twitter.com/hughskennedy">Hugh Kennedy</a>’s excellent
-  <a href="http://hughsk.io/disc/">disc</a>.
+  <a href="https://twitter.com/hughskennedy">Hugh Kennedy</a>’s excellent disc.
 </p>
 
 <h2 id="browser-support">Browser Support</h2>