Update link to issue blocking JSX hoisting (facebook#2732)

Author: ForbesLindesay

packages/babel-preset-react-app/index.js

@@ -129,10 +129,7 @@ if (env === 'test') {
 
   if (env === 'production') {
     // Optimization: hoist JSX that never changes out of render()
-    // Disabled because of issues:
-    // * https://github.com/facebookincubator/create-react-app/issues/525
-    // * https://phabricator.babeljs.io/search/query/pCNlnC2xzwzx/
-    // * https://github.com/babel/babel/issues/4516
+    // Disabled because of issues: https://github.com/facebookincubator/create-react-app/issues/553
     // TODO: Enable again when these issues are resolved.
     // plugins.push.apply(plugins, [
     //   require.resolve('babel-plugin-transform-react-constant-elements')