Fix ui bug

useEffect must be used carrefully, subscribing the effect to only those
dependencies we are interested to. Otherwise, every re-render will
trigger it.

ui/src/features/radio/Radio.tsx

@@ -42,7 +42,7 @@ export function RadioToggler() {
                 onWSMessage(lastJsonMessage);
             }
         }
-    });
+    }, [lastJsonMessage]);
 
     let buttonStatus = "";
     let circleStyle = styles.circleDisconnected;