Fix animation glitch

app/src/components/Tree/TreeNode/effects/useAnimationToIndicateTopicUpdate.tsx

@@ -9,20 +9,21 @@ export function useAnimationToIndicateTopicUpdate(
 ) {
   useEffect(() => {
     if (ref.current && shouldAnimate && Date.now() - lastUpdate < 3000 && !selected) {
+      let timeout: any
       let animationFrame = requestAnimationFrame(() => {
         ref.current && ref.current.classList.add(className)
-      })
 
-      const timeout = setTimeout(
+        timeout = setTimeout(
           () =>
             (animationFrame = requestAnimationFrame(() => {
               ref.current && ref.current.classList.remove(className)
             })),
           500
         )
+      })
 
       return function cleanup() {
-        clearTimeout(timeout)
+        timeout && clearTimeout(timeout)
         animationFrame && cancelAnimationFrame(animationFrame)
       }
     }