Created by: kjin
Following suit with #2600, this PR adds http2 as an empty module in webpack configs. I don't see http to the list, which suggests that this empty mock should probably be replaced with a browser-side implementation sometime in the future (I can add a TODO if needed).
See: https://github.com/grpc/grpc-node/issues/610 (Even though it turns out the module in question seems to not be meant for the client side, I believe the lack of this mock masked the real issue)