Update JMeter screen preview

Author: vlsi

README.md

@@ -15,7 +15,7 @@
 Apache JMeter may be used to test performance both on static and dynamic resources, Web dynamic applications.
 It can be used to simulate a heavy load on a server, group of servers, network or object to test its strength or to analyze overall performance under different load types.
 
-![Image of JMeter 4.0](https://raw.githubusercontent.com/apache/jmeter/master/xdocs/images/screenshots/JMETER_4.0.png)
+<img alt="JMeter screen" src="https://raw.githubusercontent.com/apache/jmeter/master/xdocs/images/screenshots/jmeter_screen.png">
 
 Apache JMeter features include: