Update 2020-08-10-react-v17-rc.md (reactjs#3190)

Use modern syntax for a capture-phase event listener example: flags object rather than raw boolean

Author: craigkovatch

content/blog/2020-08-10-react-v17-rc.md

@@ -94,13 +94,13 @@ document.addEventListener('click', function() {
 });
 ```
 
-You can fix code like this by converting your listener to use the [capture phase](https://javascript.info/bubbling-and-capturing#capturing). To do this, you can pass `true` as the third argument to `document.addEventListener`:
+You can fix code like this by converting your listener to use the [capture phase](https://javascript.info/bubbling-and-capturing#capturing). To do this, you can pass `{ capture: true }` as the third argument to `document.addEventListener`:
 
 ```js
 document.addEventListener('click', function() {
   // Now this event handler uses the capture phase,
   // so it receives *all* click events below!
-}, true);
+}, { capture: true });
 ```
 
 Note how this strategy is more resilient overall -- for example, it will probably fix existing bugs in your code that happen when `e.stopPropagation()` is called outside of a React event handler. In other words, **event propagation in React 17 works closer to the regular DOM**.