[#712] Fix minor issue in EagerElementCollectionForEmbeddedEmbeddableMapTest

Author: DavideD

hibernate-reactive-core/src/test/java/org/hibernate/reactive/EagerElementCollectionForEmbeddedEmbeddableMapTest.java

@@ -216,7 +216,7 @@ public void persistAnotherPersonWithStageAPI(TestContext context) {
 	public void persistCollectionOfNullsWithStageAPI(TestContext context) {
 		Person secondPerson = new Person( 9910000, "Kitty", new Phone( MOBILE, "123") );
 		secondPerson.getAlternativePhones().put( "xxx", null );
-		secondPerson.getAlternativePhones().put( "xxx", null );
+		secondPerson.getAlternativePhones().put( "yyy", null );
 
 		Stage.Session session = openSession();