Move newline for prettier print

This closes apache/maven-shared#23
diff --git a/src/main/java/org/apache/maven/shared/utils/xml/PrettyPrintXMLWriter.java b/src/main/java/org/apache/maven/shared/utils/xml/PrettyPrintXMLWriter.java
index 6623a82..deb07d2 100644
--- a/src/main/java/org/apache/maven/shared/utils/xml/PrettyPrintXMLWriter.java
+++ b/src/main/java/org/apache/maven/shared/utils/xml/PrettyPrintXMLWriter.java
@@ -366,10 +366,10 @@
 
         if ( docType != null )
         {
-            newLine();
             writer.write( "<!DOCTYPE " );
             writer.write( docType );
             writer.write( '>' );
+            newLine();
         }
     }