fix link

git-svn-id: https://svn.apache.org/repos/asf/archiva/trunk@1565996 13f79535-47bb-0310-9956-ffa450edef68

archiva-docs/src/site/apt/adminguide/upgrade.apt

@@ -73,6 +73,6 @@ Upgrading Archiva
   inside the Archiva application base directory (alongside <<<conf>>>, <<<data>>>
   and <<<logs>>>).
 
-  The default webapp context is now / (see {{{./adminguide/standalone.html} Standalone Distribution}})
+  The default webapp context is now / (see {{{./standalone.html} Standalone Distribution}})