Fix for xml handling

builders/windows-builder.py

@@ -183,9 +183,8 @@ class WindowsBuilder(Builder):
         self._print_verbose('Creating XML fragments from files and directories')
         fragments = self._get_fragments_from_files(self.dist_path)
         self._print_verbose('Inserting XML fragments into base WiX file')
-        wix = tree.getroot()
         for fragment in fragments:
-            wix.append(fragment)
+            tree.append(fragment)
         self._print_verbose('Writing new WiX file')
         with open(os.path.join(self.config_path, 'OpenLP.wxs'), 'wb') as f:
             f.write(tostring(tree, encoding='utf-8', xml_declaration=True, pretty_print=True))