Case-insensitively check the content-encoding header

[bodinsamuel]

Some server are uppercasing the content-encoding header.

Example to reproduce:
https://typespublisher.blob.core.windows.net/typespublisher/data/search-index-min.json

[sindresorhus]

Would probably be better to switch to use https://nodejs.org/api/http.html#http_response_getheader_name

[bodinsamuel]

I never used this but I don't think got is passing a Nodejs Http Response object (based on my test right now at least it trigger a TypeError: response.getHeader is not a function), and that would be a breaking change for other packages using this one.

[sindresorhus]

Ah, you're right. I confused it with the server response object.

[bodinsamuel]

Thanks a lot 💪