[FIXED JENKINS-15976] update changelog

changelog.html

@@ -55,7 +55,9 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
-  <li class=>
+  <li class=bug>
+    Provided maven settings.xml in maven builder is lost.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-15976">issue 15976</a>)
 </ul>
 </div><!--=TRUNK-END=-->