fix the link to verifier source on the developers page. closes #326

browserid/views/developers.ejs

@@ -82,7 +82,7 @@
           server.  While a bit more complicated you can reduce your
           dependencies on others.  Refer
           to <a href="https://wiki.mozilla.org/Identity/Verified_Email_Protocol">the
-          specification</a> and the <a href="https://github.com/mozilla/browserid/tree/master/verifier">source for the reference
+          specification</a> and the <a href="https://github.com/mozilla/browserid/tree/prod/verifier">source for the reference
           validator</a>.
         </p>
       </li>