Revert "Use hardcoded Trac link in release notes" (#16724)

This reverts commit 50c8e514ba.

Change-Id: I5ca731de4fd48deac1592dc739a0dcca873f6678

WebContent/release-notes.html

@@ -84,7 +84,7 @@
         <br/>
         <p>
             You can also view the <a
-                href="http://dev.vaadin.com/query?status=pending-release&status=released&resolution=fixed&milestone=Vaadin+7.4.0.beta1&milestone=Vaadin+7.4.0.beta2&milestone=Vaadin+7.4.0.beta3&milestone=Vaadin+7.4.0.rc1&milestone=Vaadin+7.4.0&order=id">list
+                href="http://dev.vaadin.com/query?status=pending-release&status=released&resolution=fixed&milestone=Vaadin+@version@&order=id">list
                 of the closed issues</a> at the Vaadin developer's site.
         </p>