remove dommodule imports

Author: FredKSchott

lib/legacy/class.html

@@ -8,7 +8,6 @@
 subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 -->
 <link rel="import" href="legacy-element-mixin.html">
-<link rel="import" href="../elements/dom-module.html">
 <script>
 
   (function() {