use new Reproducible Central badge endpoint

Author: hboutemy

Diff for: README.md

@@ -4,6 +4,7 @@ Plexus-Compiler
 [![Apache License, Version 2.0, January 2004](https://img.shields.io/github/license/codehaus-plexus/plexus-compiler.svg?label=License)](http://www.apache.org/licenses/)
 [![Maven Central](https://img.shields.io/maven-central/v/org.codehaus.plexus/plexus-compiler.svg?label=Maven%20Central)](https://search.maven.org/artifact/org.codehaus.plexus/plexus-compiler)
 [![CI](https://github.com/codehaus-plexus/plexus-compiler/actions/workflows/maven.yml/badge.svg)](https://github.com/codehaus-plexus/plexus-compiler/actions/workflows/maven.yml)
+[![Reproducible Builds](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/jvm-repo-rebuild/reproducible-central/master/content/org/codehaus/plexus/plexus-compiler/badge.json)](https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/content/org/codehaus/plexus/plexus-compiler/README.md)
 
 This component is an Compilation API used by Apache Maven Compiler plugin on the top of different Compiler Engines: Javac, Eclipse Compiler, etc..