Describe the bug

Logging in with OIDC works, but after being redirected back to FreshRSS, I get the following error:

Bad Gateway

The proxy server received an invalid response from an upstream server.

I've done a git bisect and the commit where this issue first starts appearing is af6f7f0 added in #7772 . If I revert that specific commit, rebuild the edge image and run it, the error goes away. Seems like an incompatibility of some kind in the newer versions of Apache/PHP included in Debian 13.

To Reproduce

1. Run FreshRSS using the following docker compose with an OIDC provider configured (I'm using Authelia configured as per the docs):

services:
  freshrss:
    image: freshrss/freshrss:edge
    ports:
      - 8080:80
    environment:
      CRON_MIN: 2,32
      OIDC_ENABLED: 1
      OIDC_PROVIDER_METADATA_URL: https://<REDACTED>/.well-known/openid-configuration
      OIDC_CLIENT_ID: <REDACTED>
      OIDC_CLIENT_SECRET: <REDACTED>
      OIDC_CLIENT_CRYPTO_KEY: <REDACTED>
      OIDC_REMOTE_USER_CLAIM: preferred_username
      OIDC_SCOPES: openid email profile
      OIDC_X_FORWARDED_HEADERS: X-Forwarded-Host X-Forwarded-Port X-Forwarded-Proto

2. Attempt to load the webapp
3. Sign in with OIDC provider
4. See Bad Gateway error

Expected behavior

Webapp loads with the user logged in.

FreshRSS version

1.26.3

System information

• Database version: SQLite
• PHP version: 8.4.10 (managed by docker image)
• Installation type: Docker (freshrss/freshrss:edge)
• Web server type: Apache 2.4.64 (managed by docker image)
• Device: N/A
• Host OS: Debian 12.10
• Container OS: Debian 13 RC (managed by docker image)
• Browser: Firefox 142

Additional context

No response