Summary:
The motivation is that the getting started page was not working in some cases in Firefox.
This line of code appears to be at best a no-op, at worst fails in Firefox, since "event" is undefined.
Closes https://github.com/facebook/react-native/pull/8335
Differential Revision: D3473333
Pulled By: JoelMarcey
fbshipit-source-id: 40581e83126675aa072c6ee25609cfb787015ce7