Center the navbar in the conf menu

templates/default/join.html.ep

@@ -94,6 +94,7 @@
           </button>
           <ul class="dropdown-menu" role="menu" aria-labelledby="confMenuButton" id="confMenu">
             <li>
+              <center>
                 <div class="navbar-form">
                   <div class="btn-group" data-toggle="buttons">
                     <label class="btn btn-default<%= $locked eq 'checked' ? ' btn-danger':'' %> help" id="lockLabel" data-toggle="tooltip" data-placement="bottom" title="<%=l 'PREVENT_TO_JOIN' %>">
@@ -103,6 +104,7 @@
                     </label>
                   </div>
                 </div>
+              </center>
             </li>
             <li class="divider"></li>
             <li>