Fix the name of the src for docbook property.

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@114682 13f79535-47bb-0310-9956-ffa450edef68

docbook/xdocs/properties.xml

@@ -15,7 +15,7 @@
           <th>Description</th>
         </tr>
         <tr>
-          <td>maven.src.docbook-simple</td>
+          <td>maven.docbook.src</td>
           <td>Yes</td>
           <td>
             Defaults to <code>${maven.src.dir}/sdocbook</code>. This is the