[hibernate#2108] StatelessSession insertAll in batch does not do batching

Author: dreab8

hibernate-reactive-core/src/main/java/org/hibernate/reactive/session/impl/ReactiveStatelessSessionImpl.java

@@ -150,6 +150,9 @@ private ReactiveStatelessSessionImpl(
 			PersistenceContext persistenceContext) {
 		super( factory, options );
 		this.persistenceContext = persistenceContext;
+		// StatelessSessionImpl constructor sets the Jdbc Batch Size to 0,
+		// setting it to null allows getConfiguredJdbcBatchSize() to return correct configured size
+		setJdbcBatchSize( null );
 		Integer batchSize = getConfiguredJdbcBatchSize();
 		reactiveConnection = batchSize == null || batchSize < 2
 				? connection