Upgraded Kotlin plugin

spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/util/HeaderUtils.java

@@ -71,10 +71,6 @@ public class HeaderUtils {
 		return result;
 	}
 
-	private static Collection<?> multi(Object value) {
-		return value instanceof Collection ? (Collection<?>) value : Arrays.asList(value);
-	}
-
 	public static MessageHeaders fromHttp(HttpHeaders headers) {
 		Map<String, Object> map = new LinkedHashMap<>();
 		for (String name : headers.keySet()) {
@@ -86,4 +82,8 @@ public class HeaderUtils {
 		}
 		return new MessageHeaders(map);
 	}
+
+	private static Collection<?> multi(Object value) {
+		return value instanceof Collection ? (Collection<?>) value : Arrays.asList(value);
+	}
 }