Add hideCloseButton at onCheckpointFail popup

Signed-off-by: HenrikJannsen <boilingfrog@gmx.com>

desktop/src/main/java/bisq/desktop/main/MainView.java

@@ -433,6 +433,7 @@ public class MainView extends InitializableView<StackPane, MainViewModel>
     public void onCheckpointFailed() {
         new Popup().attention(Res.get("dao.monitor.daoState.checkpoint.popup"))
                 .useShutDownButton()
+                .hideCloseButton()
                 .show();
     }