Columns menu in Explorer interface is enabled only in Details view

Source commit: 8fce142004eee924760de1bdda30aeb7ee30f859

source/forms/ScpExplorer.cpp

@@ -443,4 +443,6 @@ void __fastcall TScpExplorerForm::UpdateControls()
   {
     ActiveControl = RemoteDirView;
   }
+
+  ColumndsSubmenuItem->Enabled = (RemoteDirView->ViewStyle == vsReport);
 }