use loadlatest flag for loading app for height

cmd/zetacored/root.go

@@ -300,7 +300,7 @@ func (ac appCreator) appExport(
 
 	// If height is -1, it means we are using the latest height.
 	// For all other cases, we load the specified height from the Store
-	if height != -1 {
+	if !loadLatest {
 		if err := zetaApp.LoadHeight(height); err != nil {
 			return servertypes.ExportedApp{}, err
 		}