Fix identity store 'key not found' response (#7267)
Fix identity store 'key not found' response (#7267)

The existing custom response results in a 400 instead of the typical
404 which confuses the Terraform provider (and is inconsistent).
hashicorp/vault,joelthompson/vault,kingland/vault,rnaveiras/vault,hartsock/vault,joelthompson/vault,hashicorp/vault,kingland/vault,kingland/vault,hartsock/vault,quixoten/vault,rnaveiras/vault,hashicorp/vault,quixoten/vault,rnaveiras/vault,hartsock/vault,hartsock/vault,joelthompson/vault,quixoten/vault,rnaveiras/vault,kingland/vault,hashicorp/vault,quixoten/vault,hartsock/vault,kingland/vault,hashicorp/vault,joelthompson/vault,hashicorp/vault,rnaveiras/vault