storage: blocking proxy blocks "non-blocked" origin

Non-blocked origin is failing the ingestion [1]

As a side note, the status seems not to be updated in the webapp staging too. [2]

[1] Refs. swh/infra/sysadm-environment#5315 (comment 173597)

[2] https://webapp.staging.swh.network/save/list/

(only deployed in staging)

@douardda btw