22b9ced6c0
This will allow us to test protocol 2 in a stage environment before removing the override to make 2 the default. We may have seen a bug where something in celery (or an associated library) was adding headers to a v1 message as if it were a v2 message, which caused a bug in ddtrace; such things may become more likely over time as code is written with the assumption of v2 messages. Moving to v2 will avoid those issues. See https://github.com/edx/edx-arch-experiments/issues/800 for further details.