fix link class on list-header test

Author: BenOsodrac

core/src/components/list-header/test/basic/index.html

@@ -42,7 +42,7 @@
               Title
               <p>With list + link</p>
             </ion-label>
-            <a class="ionic-link" href="#">Clear</a>
+            <a href="#">Clear</a>
           </ion-list-header>
           <ion-item lines="none">
             <ion-label color="primary">List item</ion-label>