Fix implementation of PoolingConnectionFactoryBean.createXAContext()

Closes gh-7306

spring-boot/src/main/java/org/springframework/boot/jta/bitronix/PoolingConnectionFactoryBean.java

@@ -148,7 +148,7 @@ public class PoolingConnectionFactoryBean extends PoolingConnectionFactory
 
 		@Override
 		public XAJMSContext createXAContext(String username, String password) {
-			return this.createXAContext(username, password);
+			return this.connectionFactory.createXAContext(username, password);
 		}
 
 	}