DigestClient.prototype.fetch incorrectly overwrites headers on forwarded request

[wgehring-ml]

DigestClient.prototype.fetch is currently expecting its arguments to be in the form (url: string, init: RequestInit), but the fetch API also supports arguments in the form of (request: RequestInfo, init: undefined). This means when passing a proxied request to a client's fetch implementation, all of the original request's headers are lost.

[devfans]

DigestClient.prototype.fetch is currently expecting its arguments to be in the form (url: string, init: RequestInit), but the fetch API also supports arguments in the form of (request: RequestInfo, init: undefined). This means when passing a proxied request to a client's fetch implementation, all of the original request's headers are lost.

Hi, I was planning to fix the compatibility issue with the latest fetch version, but didn't get some free time yet. So maybe need some weeks for this to be resolved. Feel free to submit PRs tho.