Fixed date format that Doxia complains about

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1748456 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/site/apt/advanced-descriptor-topics.apt.vm b/src/site/apt/advanced-descriptor-topics.apt.vm
index c362550..02ca1b4 100644
--- a/src/site/apt/advanced-descriptor-topics.apt.vm
+++ b/src/site/apt/advanced-descriptor-topics.apt.vm
@@ -3,7 +3,7 @@
   ---
   John Casey
   ---
-  1 December 2006
+  2006-12-01
   ---
 
 ~~ Licensed to the Apache Software Foundation (ASF) under one
diff --git a/src/site/apt/advanced-module-set-topics.apt.vm b/src/site/apt/advanced-module-set-topics.apt.vm
index 3a6564f..79f1525 100644
--- a/src/site/apt/advanced-module-set-topics.apt.vm
+++ b/src/site/apt/advanced-module-set-topics.apt.vm
@@ -3,7 +3,7 @@
   ---
   John Casey
   ---
-  1 December 2006
+  2006-12-01
   ---
 
 ~~ Licensed to the Apache Software Foundation (ASF) under one