GH-3132: Remove usage of super();

Fixes https://github.com/spring-projects/spring-integration/issues/3132

It turns out that Checkstyle EmptyBlock doesn't complain about
empty default ctor.
Plus a new check for `super();` call treats it as a violation

* Remove `super();` from all the no-arg ctors
* Code style clean up in the affected classes according
IDEA suggestions

* Fix new Sonar smells

spring-integration-redis/src/main/java/org/springframework/integration/redis/channel/SubscribableRedisChannel.java

@@ -208,7 +208,6 @@ public class SubscribableRedisChannel extends AbstractMessageChannel
 	private class MessageListenerDelegate {
 
 		MessageListenerDelegate() {
-			super();
 		}
 
 		@SuppressWarnings({ "unused" })

spring-integration-redis/src/main/java/org/springframework/integration/redis/inbound/RedisInboundChannelAdapter.java

@@ -164,7 +164,6 @@ public class RedisInboundChannelAdapter extends MessageProducerSupport {
 	private class MessageListenerDelegate {
 
 		MessageListenerDelegate() {
-			super();
 		}
 
 		@SuppressWarnings("unused")

spring-integration-redis/src/main/java/org/springframework/integration/redis/inbound/RedisQueueInboundGateway.java

@@ -359,7 +359,6 @@ public class RedisQueueInboundGateway extends MessagingGatewaySupport
 	private class ListenerTask implements SchedulingAwareRunnable {
 
 		ListenerTask() {
-			super();
 		}
 
 		@Override

spring-integration-redis/src/main/java/org/springframework/integration/redis/inbound/RedisQueueMessageDrivenEndpoint.java

@@ -336,7 +336,6 @@ public class RedisQueueMessageDrivenEndpoint extends MessageProducerSupport
 	private class ListenerTask implements SchedulingAwareRunnable {
 
 		ListenerTask() {
-			super();
 		}
 
 		@Override

spring-integration-redis/src/main/java/org/springframework/integration/redis/outbound/RedisOutboundGateway.java

@@ -143,7 +143,6 @@ public class RedisOutboundGateway extends AbstractReplyProducingMessageHandler {
 	private static class PayloadArgumentsStrategy implements ArgumentsStrategy {
 
 		PayloadArgumentsStrategy() {
-			super();
 		}
 
 		@Override

spring-integration-redis/src/main/java/org/springframework/integration/redis/support/RedisHeaders.java

@@ -29,7 +29,6 @@ package org.springframework.integration.redis.support;
 public final class RedisHeaders {
 
 	private RedisHeaders() {
-		super();
 	}
 
 	public static final String PREFIX = "redis_";