fix import order

Change-Id: I62dfdb5f0af73b5402fc63d57c5a9659f77b9a94

Author: zzzeek

mako/pyparser.py

@@ -10,9 +10,8 @@
 module is used.
 """
 
-import operator
-
 import _ast
+import operator
 
 from mako import _ast_util
 from mako import compat