Requests fail because browser emulator changes accept-language

[soundofspace]

Unblocked changes accept-language, because headless chrome doesn't always fill this in correctly. This breaks some websites where they manually overwrite this header with something custom/they expect.

To fix this there are multiple options:

1. Remove this overwrite. Seems like chrome is doing it correctly now, and Unblocked is not following chrome behaviour.
2. Only overwrite this when needed. How to detect?
3. Only overwrite if request !isXhr. Info is there but is that enough?

Data to suggest that chrome is doing it correctly now, tested using chrome 109:

Locale set	Hero with overwrite	Headful Hero	Headless Hero	Native Chrome
nothing	en-US,en;q=0.9	en-US,en;q=0.9	en-US,en;q=0.9	en-US,en;q=0.9
bg_BG	bg_BG;q=0.9	bg_BG	bg_BG	bg
en-US	en-US;q=0.9	en-US	en-US	en-US
en-US,en	en-US,en;q=0.9	en-US,en;q=0.9	en-US,en;q=0.9	en-US,en;q=0.9