Remove unused help link from dropdown in nav

We don't use the FAQ/Help link embedded in the name/logout drop-
down in the navigation bar, so remove it.

lms/templates/navigation.html

@@ -70,10 +70,6 @@ site_status_msg = get_site_status_msg(course_id)
       <li class="primary">
         <a href="#" class="dropdown">&#9662</a>
         <ul class="dropdown-menu">
-            <li>
-            <a href="${marketing_link('FAQ')}">
-            Help
-          </a></li>
           <li><a href="${reverse('logout')}">Log Out</a></li>
         </ul>
       </li>