Issues with grpc-web 1.0.7 + envoy 1.13 + Safari 13

Hi!

My team uses grpc-web at the latest version (1.0.7). We recently upgraded our server to use Envoy 1.13, and with this upgrade, Safari could no longer receive functional responses from Envoy. Other browsers were unaffected. We then downgraded Envoy to 1.12, and the issue was resolved. So there seems to be an incompatibility with:
- grpc-web 1.0.7
- envoy 1.13
- safari 13 (did not test other versions)

We also noticed that last release of grpc-web was made in November 2019, and there have been some commits made since then that _might_ address this compatibility issue. I tried to point our web app to grpc-web's master branch, but npm makes this rather difficult if the package.json is not in the root :) so I gave up after a while.

So just wanted to check:
- Is this something you're aware of?
- Do you plan to release a new version to npm soon?