Fix deadlock in TestPostgreSQLBackend (#6884)
Fix deadlock in TestPostgreSQLBackend (#6884)

Make lock2's retryInterval smaller so it grabs the lock as soon as lock1's renewer fails to renew in time.  Fix the logic to test if lock1's leader channel gets closed: we don't need a goroutine, and
the logic was broken in that if we timed out we'd never write to the blocking channel we then try to read from.  Moreover the timeout was wrong.


hashicorp/vault,quixoten/vault,hashicorp/vault,hartsock/vault,kingland/vault,joelthompson/vault,hashicorp/vault,joelthompson/vault,joelthompson/vault,rnaveiras/vault,hashicorp/vault,hartsock/vault,rnaveiras/vault,joelthompson/vault,hartsock/vault,hashicorp/vault,kingland/vault,quixoten/vault,rnaveiras/vault,hashicorp/vault,quixoten/vault,rnaveiras/vault,hartsock/vault,hartsock/vault,kingland/vault,quixoten/vault,rnaveiras/vault,kingland/vault,kingland/vault