Don't report 'message' as 'null'
Don't report 'message' as 'null'

Summary: This can confuse consumers of the stream, so avoid setting 'message' entirely.

Reviewed By: k21

Differential Revision: D3791619

fbshipit-source-id: 207332abad06525588e0408affb14f4b6fd83454

bootstraponline/FBSimulatorControl,facebook/FBSimulatorControl,StevenUpForever/FBSimulatorControl,plu/FBSimulatorControl,bootstraponline/FBSimulatorControl,bootstraponline/FBSimulatorControl,plu/FBSimulatorControl,StevenUpForever/FBSimulatorControl,facebook/FBSimulatorControl,ichu501/FBSimulatorControl,plu/FBSimulatorControl,bootstraponline/FBSimulatorControl,facebook/FBSimulatorControl,plu/FBSimulatorControl,facebook/FBSimulatorControl,StevenUpForever/FBSimulatorControl,facebook/FBSimulatorControl,StevenUpForever/FBSimulatorControl