lxml.etree is the wrong location for this alt package

  on my linux machine this is the correct one. lxml.etree
  exists with an ElementTree class, but does not contain
  an .XML method.

R=rsc
https://golang.org/cl/163082
diff --git a/lib/codereview/codereview.py b/lib/codereview/codereview.py
index 51f9b8e..41f74d2 100644
--- a/lib/codereview/codereview.py
+++ b/lib/codereview/codereview.py
@@ -46,7 +46,7 @@
 try:
 	from xml.etree import ElementTree as ET
 except:
-	from lxml.etree import ElementTree as ET
+	from elementtree import ElementTree as ET
 
 try:
 	hgversion = util.version()