Update link to API changes report

Since a long time we use japicmp and no longer clirr, but forgot to
update the link on the download site.

Change-Id: Ie30125fd0a339d17e5106d227e1524bc13c3200d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
diff --git a/download/_index.html b/download/_index.html
index ae0995e..0b69489 100644
--- a/download/_index.html
+++ b/download/_index.html
@@ -5,7 +5,7 @@
 <li><a href="@MAVEN_REPO@/org/eclipse/jgit/org.eclipse.jgit.pgm/@VERSION@/org.eclipse.jgit.pgm-@VERSION@.sh">jgit.sh</a> (Self-contained command line executable)</li>
 <li><a href="http://download.eclipse.org/jgit/site/@API_VERSION@/">JGit @API_VERSION@ Projects Overview</a> (Maven Site)</li>
 <li><a href="http://download.eclipse.org/jgit/site/@API_VERSION@/apidocs/index.html">org.eclipse.jgit JavaDoc</a> (online JavaDoc)</li>
-<li><a href="http://download.eclipse.org/jgit/site/@API_VERSION@/org.eclipse.jgit/clirr-report.html">JGit API changes since previous release</a> (online Clirr API changes report)</li>
+<li><a href="http://download.eclipse.org/jgit/site/@API_VERSION@/org.eclipse.jgit/japicmp.html">JGit API changes since previous release</a> (online japicmp API changes report)</li>
 </ul>
 
 Find the list of older JGit versions <a href="http://wiki.eclipse.org/JGit/FAQ#Where_can_I_find_older_releases_of_JGit.3F">here</a>.