Remove setThreadManager in CppServerWrapper.cpp
Remove setThreadManager in CppServerWrapper.cpp

Summary: Add a thrift flag and code to migrate away from setThreadManager in CppServerWrapper. This is used in hundreds of binaries so we will roll it out separately.

Reviewed By: iahs

Differential Revision: D40477622

fbshipit-source-id: bbdb9f3e0258d1be56e2235df86c2018da973888

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