message: Partially revert "fix build problems from merges" again
  This reverts a change in ConnectionHandlerImpl of
  commit which was
  to workaround a build failure with ENABLE_SECURITY=OFF.
  The issue has been resolved with latest develop so the
  workaround is no longer needed.
diff: @@ -466,11 +466,8 @@ void ConnectionHandlerImpl::OnSessionStartedCallback(
  }
  Connection* connection = it->second;
  -
  -#ifdef ENABLE_SECURITY
  context.is_new_service_ =
  !connection->SessionServiceExists(session_id, service_type);
  -#endif // ENABLE_SECURITY
  if ((0 == session_id) && (protocol_handler::kRpc == service_type)) {
  context.new_session_id_ =
  