Fix broken link (#1361)

content/blog/2018-10-01-create-react-app-v2.md

@@ -59,7 +59,7 @@ Here are a few more tips to get you started.
 
 **When you run `npm start` for the first time after the upgrade,** you'll get a prompt asking about which browsers you'd like to support. Press `y` to accept the default ones. They'll be written to your `package.json` and you can edit them any time. Create React App will use this information to produce smaller or polyfilled CSS bundles depending on whether you target modern browsers or older browsers.
 
-**If `npm start` still doesn't quite work for you after the upgrade,** [check out the more detailed migration instructions in the release notes](https://github.com/facebook/create-react-app/releases/tag/v2.0.3). There *are* a few breaking changes in this release but the scope of them is limited, so they shouldn't take more than a few hours to sort out. Note that **[support for older browsers](https://github.com/facebook/create-react-app/blob/next/packages/react-app-polyfill/README.md) is now opt-in** to reduce the polyfill size.
+**If `npm start` still doesn't quite work for you after the upgrade,** [check out the more detailed migration instructions in the release notes](https://github.com/facebook/create-react-app/releases/tag/v2.0.3). There *are* a few breaking changes in this release but the scope of them is limited, so they shouldn't take more than a few hours to sort out. Note that **[support for older browsers](https://github.com/facebook/create-react-app/blob/master/packages/react-app-polyfill/README.md) is now opt-in** to reduce the polyfill size.
 
 **If you previously ejected but now want to upgrade,** one common solution is to find the commits where you ejected (and any subsequent commits changing the configuration), revert them, upgrade, and later optionally eject again. It's also possible that the feature you ejected for (maybe Sass or CSS Modules?) is now supported out of the box.