Check for nil value in BarrierView.Put (#4804)
Check for nil value in BarrierView.Put (#4804)

Fixes #4802
joelthompson/vault,hartsock/vault,rnaveiras/vault,rnaveiras/vault,hashicorp/vault,joelthompson/vault,kingland/vault,hartsock/vault,quixoten/vault,quixoten/vault,hartsock/vault,rnaveiras/vault,kingland/vault,joelthompson/vault,hashicorp/vault,kingland/vault,kingland/vault,quixoten/vault,hashicorp/vault,kingland/vault,hashicorp/vault,rnaveiras/vault,rnaveiras/vault,hartsock/vault,quixoten/vault,hartsock/vault,joelthompson/vault,hashicorp/vault,hashicorp/vault