Remove unused stree import (since stree is no more!)

diff --git a/samples/servlet/ApplyXSLT.java b/samples/servlet/ApplyXSLT.java
index a143950..c235a84 100644
--- a/samples/servlet/ApplyXSLT.java
+++ b/samples/servlet/ApplyXSLT.java
@@ -84,7 +84,6 @@
 import javax.xml.transform.stream.*;
 import javax.xml.transform.sax.SAXTransformerFactory;
 import org.apache.xalan.transformer.TransformerImpl;
-import org.apache.xalan.stree.SourceTreeHandler;
 import org.apache.xpath.objects.XObject;
 import org.apache.xpath.objects.XString;
 import org.apache.xalan.processor.*;