Title: Old envoyproxy/ratelimit leads to crash
Description:
Forwarding an issue from our repo: istio/istio#30900

Basically, it sounds like when missing transport_api_version in the rate limiting config, we get a crash

Expected behavior is some more graceful failure, probably a NACK

Repro steps:
See istio/istio#30900. I did not reproduce myself, just forwarding this