Issue apache#3373: RemotelyClosedException when running SampleProducer

*Motivation*

Fixes apache#3373 

The service url in SampleProducer is wrong.

*Modification*

Fix the service url in SampleProducer and SampleConsumer.

pulsar-client/src/test/java/org/apache/pulsar/client/tutorial/SampleConsumer.java

@@ -26,7 +26,7 @@
 public class SampleConsumer {
     public static void main(String[] args) throws PulsarClientException, InterruptedException {
 
-        PulsarClient pulsarClient = PulsarClient.builder().serviceUrl("http://localhost:8080").build();
+        PulsarClient pulsarClient = PulsarClient.builder().serviceUrl("pulsar://localhost:6650").build();
 
         Consumer<byte[]> consumer = pulsarClient.newConsumer() //
                 .topic("persistent://my-tenant/my-ns/my-topic") //

pulsar-client/src/test/java/org/apache/pulsar/client/tutorial/SampleProducer.java

@@ -26,7 +26,7 @@
 
 public class SampleProducer {
     public static void main(String[] args) throws PulsarClientException, InterruptedException, IOException {
-        PulsarClient client = PulsarClient.builder().serviceUrl("http://localhost:6650").build();
+        PulsarClient client = PulsarClient.builder().serviceUrl("pulsar://localhost:6650").build();
 
         Producer<byte[]> producer = client.newProducer().topic("persistent://my-tenant/my-ns/my-topic").create();