fix a segfault on HTTP fetch when there is no flow assigned in the transport and OAuth fails
fix a segfault on HTTP fetch when there is no flow assigned in the transport and OAuth fails

google/google-api-cpp-client,abpoms/google-api-cpp-client,google/google-api-cpp-client,abpoms/google-api-cpp-client,abpoms/google-api-cpp-client,google/google-api-cpp-client