free5GC's NEF 3gpp-pfd-management PATCH applications/{appId} panics on UDR access failure due to nil ProblemDetails dereference

Summary free5GC's NEF PATCH /3gpp-pfd-management/v1/afId/transactions/transId/applications/appId handler panics with a nil-pointer dereference when the upstream UDR call fails AND the consumer wrapper returns err != nil together with a nil ProblemDetails. The handler's errPfdData != nil branch...