Expected behavior

The default nack backoff policy should return the maximum backoff time once reaching an arbitrary high redelivery count.

Actual behavior

The default nack backoff policy returns zero once a sufficiently big redelivery count is reached.

Steps to reproduce

func TestDefaultNackBackoffPolicy_Next(t *testing.T) {
	defaultNackBackoff := new(defaultNackBackoffPolicy)

	res := defaultNackBackoff.Next(math.MaxUint32)
	assert.Equal(t, 10*time.Minute, res)
}

System configuration

Pulsar version: v4.0.5
Pulsar Go client: v0.15.1