tests: move stdlib imports before mercurial modules in test-parseindex2

tests/test-parseindex2.py

@@ -4,6 +4,11 b' It also checks certain aspects of the pa'
 """
 
 from __future__ import absolute_import, print_function
+
+import struct
+import subprocess
+import sys
+
 from mercurial import (
     parsers,
 )
@@ -11,9 +16,6 b' from mercurial.node import ('
     nullid,
     nullrev,
 )
-import struct
-import subprocess
-import sys
 
 # original python implementation
 def gettype(q):