thorax: remove count from clear completed button

Ref #1234

examples/thorax/index.html

@@ -48,7 +48,7 @@
 				</li>
 			</ul>
 			{{#if completed}}
-				<button id="clear-completed">Clear completed ({{completed}})</button>
+				<button id="clear-completed">Clear completed</button>
 			{{/if}}
 		</script>
 		<script src="bower_components/todomvc-common/base.js"></script>