[FAQ][Medium] http-servers-support.md: dead anchor link

[lyzhang0113]

File: _articles/faq/http-servers-support.md
Severity: Medium

Found via a full FAQ accuracy audit for dead links.

Claim: "we recommend the API here"

Contradicting evidence: image-export/index.md has no "Upload" heading/anchor — it's a bare table of contents. The actual upload content lives in the sibling server-upload.md.

Proposed fix: Point to /_articles/general-usage/image-export/server-upload.md instead.

[lyzhang0113]

Confirmed. Use this:
https://www.dynamsoft.com/web-twain/docs/general-usage/image-export/server-upload.html#uploading-over-http

This entire FAQ needs a refresh, or rephrase though. Consider that when fixing.