modified version of plugin in README

Author: anthonygauthier

README.md

@@ -56,7 +56,7 @@ JMeter ElasticSearch Backend Listener is a JMeter plugin enabling you to send te
 <dependency>
   <groupId>io.github.delirius325</groupId>
   <artifactId>jmeter.backendlistener.elasticsearch</artifactId>
-  <version>2.6.5</version>
+  <version>2.6.6</version>
 ```
 
 ## Contributing