Polish "Fix content negotiation for /vets"

Closes gh-326

src/main/java/org/springframework/samples/petclinic/vet/VetController.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

src/main/resources/templates/vets/vetList.html

@@ -23,12 +23,5 @@
       </tr>
     </tbody>
   </table>
-
-  <table class="table-buttons">
-    <tr>
-      <td><a th:href="@{/vets}">View as XML</a></td>
-    </tr>
-  </table>
-
 </body>
 </html>