* Rebase and fix conflicts

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/endpoint/AbstractPollingEndpoint.java

@@ -72,6 +72,8 @@ public abstract class AbstractPollingEndpoint extends AbstractEndpoint implement
 
 	private Executor taskExecutor = new SyncTaskExecutor();
 
+	private boolean syncExecutor = true;
+
 	private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
 
 	private Trigger trigger = new PeriodicTrigger(10);

spring-integration-core/src/main/java/org/springframework/integration/endpoint/SourcePollingChannelAdapter.java

@@ -30,7 +30,6 @@
 import org.springframework.integration.StaticMessageHeaderAccessor;
 import org.springframework.integration.acks.AckUtils;
 import org.springframework.integration.acks.AcknowledgmentCallback;
-import org.springframework.integration.aop.AbstractMessageSourceAdvice;
 import org.springframework.integration.aop.MessageSourceMutator;
 import org.springframework.integration.channel.ReactiveStreamsSubscribableChannel;
 import org.springframework.integration.context.ExpressionCapable;