CURA-4525 do not show build plate view item when disabled

resources/qml/Menus/ViewMenu.qml

@@ -50,6 +50,7 @@ Menu
     {
         id: buildPlateMenu;
         title: catalog.i18nc("@action:inmenu menubar:view","&Build plate");
+        visible: UM.Preferences.getValue("cura/use_multi_build_plate")
         Instantiator
         {
             model: Cura.BuildPlateModel

resources/qml/ObjectsList.qml

@@ -231,7 +231,6 @@ Rectangle
         tooltip: '';
         anchors
         {
-            //top: buildPlateSelection.bottom;
             topMargin: UM.Theme.getSize("default_margin").height;
             left: parent.left;
             leftMargin: UM.Theme.getSize("default_margin").height;