Ordered consumer start time fix (#424)

When initial request delivery policy is by time
all subsequent request should still start by
sequence and reset start-time field to avoid
errors returned by server.

src/NATS.Client.JetStream/NatsJSOrderedConsumer.cs

@@ -273,6 +273,7 @@ private async Task<NatsJSConsumer> RecreateConsumer(string consumer, ulong seq,
             {
                 OptStartSeq = seq + 1,
                 DeliverPolicy = ConsumerConfigDeliverPolicy.ByStartSequence,
+                OptStartTime = default,
             };
 
             if (consumer != string.Empty)