`migrations.ALLOWED_DOMAINS` doesn't work as expected with `PROXY_URL` set

[wolfogre]

Description

If Gitea starts with config:

[proxy]
PROXY_ENABLED = true
PROXY_URL = http://127.0.0.1:7890
PROXY_HOSTS = *.github.com,github.com

[migrations]
ALLOWED_DOMAINS = "" ; blank means external hosts will be allowed

It will fail to migrate repos from github.com.

Enabling ALLOW_LOCALNETWORKS can resolve it, but it's not the way as expected.

Gitea Version

main (d9a7748)

Can you reproduce the bug on the Gitea demo site?

No

Log Gist

No response

Screenshots

No response

Git Version

No response

Operating System

No response

How are you running Gitea?

Command with binary.

Database

SQLite

[wolfogre]

I believe it's an overlooked similar work of #27655.

[lunny]

Because proxy url should be added to allowed migration url automatically?