Disable fuzzy matching when distanceLimit = 0

Before this commit, fuzzy matching is performed even though exact
matching is requested (distanceLimit = 0).

This commit bypasses fuzzy matching when distanceLimit = 0 which
improves performance.

Resolves BATCH-1801

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/mapping/BeanWrapperFieldSetMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -91,6 +91,7 @@
  * match is found. If more than one match is found there will be an error.
  * 
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  * 
  */
 public class BeanWrapperFieldSetMapper<T> extends DefaultPropertyEditorRegistrar implements FieldSetMapper<T>,
@@ -259,6 +260,10 @@ private T getBean() {
 	 */
 	private Properties getBeanProperties(Object bean, Properties properties) {
 
+		if (this.distanceLimit == 0) {
+			return properties;
+		}
+
 		Class<?> cls = bean.getClass();
 
 		// Map from field names to property names