[bug] Non-root APPLICATION_URL renders application non-functional

[jtagcat]

Description of the bug

APPLICATION_URL=https://example.com/filestash_lives_here

Reverse proxy only exposes /filestash_lives_here and all subdirectories.

Observed behavior

404 (filestash thinks its root is https://example.com, not https://example.com/filestash_lives_here)

Expected behavior

/ is 404

[mickael-kerjean]

We don't support that use case at the moment, there's some PR that got started but never completed, this would have to come from the community as my wish list has no spare room