Inline Docs: Update incorrect docs for HTTP functions

[kraftbj]

is_allowed_http_origin function inline docs state the return is True if the origin is allowed. False otherwise., which is not true.

The return is the result of get_http_origin (or the passed value) or an empty string.

[kraftbj]

Updates inline docs

[SergeyBiryukov]

In 36398:

Docs: Correct return value for is_allowed_http_origin().

Props kraftbj.
Fixes #35607.