fixed pdf reference doc build error

Spring.build

@@ -818,7 +818,7 @@ Examples:
   </target>
 
   <target name="doc-reference">
-    <nant buildfile="./doc/reference/docbook.build" target="all"/>
+    <nant buildfile="./doc/reference/docbook.build" />
   </target>
 
   <target name="doc-sdk">

doc/reference/docbook.build

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<project name="DocBook" default="help" xmlns="http://nant.sf.net/release/0.85/nant.xsd">
+<project name="DocBook" default="pdf" xmlns="http://nant.sf.net/release/0.85/nant.xsd">
 
   <property name="project.basedir" value="${project::get-base-directory()}" />
   <property name="project.targetdir" value="${project.basedir}\target" />

doc/reference/src/vsnet.xml

@@ -58,8 +58,8 @@
     include the schema as part of your application project.</para>
 
     <programlisting language="myxml">&lt;?xml version="1.0" encoding="UTF-8"?&gt;
-&lt;objects xmlns="http://www.springframework.net" 
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
+&lt;objects xmlns="http://www.springframework.net"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://www.springframework.net http://www.springframework.net/xsd/spring-objects.xsd"&gt;
   &lt;object id="..." type="..."&gt;
   ...
@@ -112,10 +112,6 @@
       </tgroup>
     </table>
 
-    <table>
-      <title />
-    </table>
-
     <para>Spring's .xsd schemas are located in the directory doc/schema. In
     that directory is also a NAnt build file to help copy over the .xsd files
     to the appropriate VS.NET locations. To execute this script simply type
@@ -160,7 +156,7 @@
     &lt;context&gt;
       &lt;resource uri="config://spring/objects"/&gt;
     &lt;/context&gt;
-       
+
     &lt;objects xmlns="http://www.springframework.net"&gt;
         ...
     &lt;/objects&gt;