GH-2667: Use any Number for inbound x-delay property

Fixes: #2667

The `x-delay` header may arrive as a `Short` from RabbitMQ broker.

* Fix `DefaultMessagePropertiesConverter.toMessageProperties()` to deal with a `Number`
to extract `long` value from the `x-delay` header

# Conflicts:
#	spring-rabbit/src/main/java/org/springframework/amqp/rabbit/support/DefaultMessagePropertiesConverter.java

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/support/DefaultMessagePropertiesConverter.java

@@ -40,6 +40,8 @@
  * @author Mark Fisher
  * @author Gary Russell
  * @author Soeren Unruh
+ * @author Artem Bilan
+ *
  * @since 1.0
  */
 public class DefaultMessagePropertiesConverter implements MessagePropertiesConverter {
@@ -92,8 +94,10 @@ public MessageProperties toMessageProperties(final BasicProperties source, final
 				String key = entry.getKey();
 				if (MessageProperties.X_DELAY.equals(key)) {
 					Object value = entry.getValue();
-					if (value instanceof Integer integ) {
-						target.setReceivedDelay(integ);
+					if (value instanceof Number numberValue) {
+						int receivedDelayLongValue = numberValue.intValue();
+						target.setReceivedDelay(receivedDelayLongValue);
+						target.setHeader(key, receivedDelayLongValue);
 					}
 				}
 				else {
@@ -174,7 +178,7 @@ private Map<String, Object> convertHeadersIfNecessary(Map<String, Object> header
 	}
 
 	/**
-	 * Converts a header value to a String if the value type is unsupported by AMQP, also handling values
+	 * Convert a header value to a String if the value type is unsupported by AMQP, also handling values
 	 * nested inside Lists or Maps.
 	 * <p> {@code null} values are passed through, although Rabbit client will throw an IllegalArgumentException.
 	 * @param valueArg the value.