Merge pull request #17173 from eugenp/lor6-patch-1

Update README.md

Author: lor6

core-java-modules/core-java-9-improvements/README.md

@@ -8,5 +8,4 @@ This module contains articles about the improvements to core Java features intro
 - [Java Convenience Factory Methods for Collections](https://www.baeldung.com/java-9-collections-factory-methods)
 - [Java 9 Stream API Improvements](https://www.baeldung.com/java-9-stream-api)
 - [Java 9 java.util.Objects Additions](https://www.baeldung.com/java-9-objects-new)
-- [Java 9 CompletableFuture API Improvements](https://www.baeldung.com/java-9-completablefuture)
 - [Java InputStream to Byte Array and ByteBuffer](https://www.baeldung.com/convert-input-stream-to-array-of-bytes)