Move back to SNAPSHOTs; fix for Reactor changes

spring-integration-core/src/main/java/org/springframework/integration/channel/FluxMessageChannel.java

@@ -59,7 +59,7 @@ public class FluxMessageChannel extends AbstractMessageChannel
 	protected boolean doSend(Message<?> message, long timeout) {
 		Assert.state(this.processor.hasDownstreams(),
 				() -> "The [" + this + "] doesn't have subscribers to accept messages");
-		return this.sink.emitNext(message).hasEmitted();
+		return this.sink.tryEmitNext(message).hasSucceeded();
 	}
 
 	@Override

spring-integration-core/src/main/java/org/springframework/integration/gateway/MessagingGatewaySupport.java

@@ -894,7 +894,7 @@ public abstract class MessagingGatewaySupport extends AbstractEndpoint
 
 		@Override
 		public boolean send(Message<?> message, long timeout) {
-			return Boolean.TRUE.equals(this.replyMono.emitValue(message).hasEmitted());
+			return this.replyMono.tryEmitValue(message).hasSucceeded();
 		}
 
 		@Override

spring-integration-core/src/main/java/org/springframework/integration/util/IntegrationReactiveUtils.java

@@ -129,7 +129,7 @@ public final class IntegrationReactiveUtils {
 			Sinks.Many<Message<T>> sink = Sinks.many().multicast().onBackpressureBuffer(1);
 			@SuppressWarnings("unchecked")
 			MessageHandler messageHandler = (message) -> {
-				while (!sink.emitNext((Message<T>) message).hasEmitted()) {
+				while (!sink.tryEmitNext((Message<T>) message).hasSucceeded()) {
 					LockSupport.parkNanos(100); // NOSONAR
 				}
 			};