message: [c++ grpc] Remove disabled memory leak detection
  The global memory leak was fixed in grpc 1.12.0 in commit
diff: @@ -175,14 +175,6 @@ public:
  bool init_unit_test()
  {
  - // grpc allocates a bunch of stuff on-demand caused the leak tracker to
  - // report leaks. Disable it for this test.
  - boost::debug::detect_memory_leaks(false);
  -
  - // Initialize the gRPC++ library
  - grpc::internal::GrpcLibraryInitializer initializer;
  - initializer.summon();
  -
  io_managerTests::Initialize();
  return true;
  }
  