display 'U' in status flags while update is running if idle support is off

src/status.cpp

@@ -529,7 +529,7 @@ void NcmpcppStatusChanged(Connection *, StatusChanges changed, void *)
 	{
 		// mpd-0.{14,15} doesn't support idle notification that dbupdate had
 		// finished and nothing changed, so we need to switch it off for them.
-		if (Mpd.Version() < 14 || Mpd.Version() > 15)
+		if (!Mpd.SupportsIdle() || Mpd.Version() > 15)
 			mpd_db_updating = Mpd.GetDBIsUpdating() ? 'U' : 0;
 		ShowMessage(Mpd.GetDBIsUpdating() ? "Database update started!" : "Database update finished!");
 		if (changed.Database && myScreen == mySelectedItemsAdder)