fix sse prefix, after switching from nginx proxy to ALB
same issue as for /admin, which was fixed in three PR: https://github.com/huggingface/dataset-viewer/pull/2820, https://github.com/huggingface/dataset-viewer/pull/2821, https://github.com/huggingface/dataset-viewer/pull/2825
fix sse prefix, after switching from nginx proxy to ALB: same issue as for /admin, which was fixed in three PR: https://github.com/huggingface/dataset-viewer/pull/2820, https://github.com/huggingface/dataset-viewer/pull/2821, https://github.com/huggingface/dataset-viewer/pull/2825