Fix broken tables in panel groups example

components.html

@@ -2786,7 +2786,7 @@ body { padding-bottom: 70px; }
     <h3 id="panels-tables">With tables</h3>
     <p>Add any non-bordered <code>.table</code> within a panel for a seamless design. If there is a <code>.panel-body</code>, we add an extra border to the top of the table for separation.</p>
     <div class="bs-example">
-      <div class="panel">
+      <div class="panel panel-default">
         <!-- Default panel contents -->
         <div class="panel-heading">Panel heading</div>
         <div class="panel-body">
@@ -2827,7 +2827,7 @@ body { padding-bottom: 70px; }
       </div>
     </div>
 {% highlight html %}
-<div class="panel">
+<div class="panel panel-default">
   <!-- Default panel contents -->
   <div class="panel-heading">Panel heading</div>
   <div class="panel-body">