ui: only update ignition when panda is connected (#22425)

selfdrive/ui/ui.cc

@@ -137,7 +137,10 @@ static void update_state(UIState *s) {
   if (sm.updated("pandaState")) {
     auto pandaState = sm["pandaState"].getPandaState();
     scene.pandaType = pandaState.getPandaType();
+
+    if (scene.pandaType != cereal::PandaState::PandaType::UNKNOWN) {
       scene.ignition = pandaState.getIgnitionLine() || pandaState.getIgnitionCan();
+    }
   } else if ((s->sm->frame - s->sm->rcv_frame("pandaState")) > 5*UI_FREQ) {
     scene.pandaType = cereal::PandaState::PandaType::UNKNOWN;
   }