Remove Internet Explorer leftovers

site/content/docs/4.3/examples/navbar-static/index.html

@@ -31,7 +31,7 @@ extra_css:
   </div>
 </nav>
 
-<main role="main" class="container">
+<main class="container">
   <div class="bg-light p-5 rounded">
     <h1>Navbar example</h1>
     <p class="lead">This example is a quick exercise to illustrate how the top-aligned navbar works. As you scroll, this navbar remains in its original position and moves with the rest of the page.</p>