fix: don't change the options in httpRequestCore

[TsvetanMilanov]

Do not change the options object in the httpRequestCore method of the
$httpClient because if we do, we can't retry correctly the http requests
(e.g. we delete the body property and when we retry the request, we don't have any body to send)

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What is the current behavior?

What is the new behavior?

Fixes/Implements/Closes #[Issue Number].