The HTTP fetch provider resolved each hostname, rejected any non-public
answer, and pinned the connection. That refused every page behind
TUN-mode proxies with fake-IP DNS and did not confine a model that has
shell network access. Requests now go through the installed proxy
dispatcher and the system resolver with no address restriction.
HttpFetchResolver and the HttpFetchProvider resolver parameter are
removed; the upgrade guide covers the migration.
Co-authored-by: turtle1999 <[email protected]>