Use absolute links

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@371838 13f79535-47bb-0310-9956-ffa450edef68

developer-activity/xdocs/index.xml

@@ -31,8 +31,8 @@
         your source control system so that project team members can see
         at a glance what changes have been made recently to the project.
         This report relies on the
-        <a href="../changelog/index.html">Changelog plugin</a> for its
-        configuration.
+        <a href="http://maven.apache.org/maven-1.x/reference/plugins/changelog/">Changelog plugin</a>
+        for its configuration.
       </p>
       <p> 
         For additional information on the functionality provided by this plugin,