put threadmanager initialization in setThreadManagerInternal for RP path
put threadmanager initialization in setThreadManagerInternal for RP path

Summary: If threadmanager is not initialized in setThreadManagerInternal, the wrapper won't be properly set up

Reviewed By: roddym

Differential Revision: D36270334

fbshipit-source-id: b9170b76b8ce328b39a3e7670e7776e2fd11205b

facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift,facebook/fbthrift