Failed to construct 'Headers': No matching constructor signature.

[vipero07]

Describe the bug
Failed to construct 'Headers': No matching constructor signature. On Chrome 56m. This is uniquely an old browser issue where it cannot construct headers when its one parameter is undefined. An easy fix is to replace any new Headers(possibleUndefined) with new Headers(possibleUndefined ?? {}).

An alternative solution is to add headers to the GrpcWebTransportOptions allowing someone to override the default behavior.

same issue from a diff repo

To Reproduce
Failed to construct 'Headers': No matching constructor signature.
This issue is specific to chrome 56m, may even be specific to a Samsung TV.

createGrpcWebTransport({
      baseUrl: import.meta.env.VITE_GRPC_ENDPOINT,
      binaryOptions: {readUnknownFields: false, writeUnknownFields: false},
    })

Environment (please complete the following information):

• @bufbuild/connect-web@0.1.0
• @bufbuild/protobuf@0.0.10
• Framework and version: svelte@3.49.0
• Browser and version: Chrome 56m

Additional context
undefined headers

[timostamm]

Closed in #232