Updated DevTools CHANGELOG

Author: Brian Vaughn

packages/react-devtools/CHANGELOG.md

@@ -8,6 +8,8 @@
 
   <!-- Upcoming changes go here -->
 
+#### Bug fixes
+* Fixed regression where DevTools wouldn't properly connect with apps when using the `file://` protocol. ([linshunghuang](https://github.com/linshunghuang) in [#16953](https://github.com/facebook/react/pull/16953))
 </details>
 
 ## 4.1.2 (September 27, 2019)