openwisp-controller: OpenWISP Controller CA CRL REST API does not scope requests to managed organizations

OpenWISP Controller is a network and WiFi controller for provisioning, configuration management, updates, and PKI management. From 1.0.0 until 1.3.2, the GET /api/v1/controller/ca/<integer-id>/crl endpoint allows an authenticated organization manager with CA view permission to retrieve another organization's certificate revocation list by requesting its sequential CA identifier. CrlDownloadView.retrieve resolves the CA directly instead of using the organization-scoped object retrieval enforced by FilterByOrganizationManaged, bypassing the endpoint's intended authorization boundary. The response can disclose CA issuer information and revoked certificate serial numbers, but it does not expose CA private keys or allow modification. This issue is fixed in version 1.3.2.