Fixes qa#113: Add an empty main menu item causes an error

--HG--
branch : dev

src/Orchard.Web/Core/Navigation/Controllers/AdminController.cs

@@ -43,7 +43,7 @@ namespace Orchard.Core.Navigation.Controllers {
             if (model.MenuItemEntries == null || model.MenuItemEntries.Count() < 1)
                 model.MenuItemEntries = _menuService.Get().Select(CreateMenuItemEntries).OrderBy(menuPartEntry => menuPartEntry.MenuItem.Position, new PositionComparer()).ToList();
 
-            return View(model);
+            return View("Index", model);
         }
 
         [HttpPost, ActionName("Index")]