Undo redundant imports & new-style raises

New-style rasies need to be redone in a py2-friendly way, and the
redudant imports are redudnant and can safely be removed

setup/git_pre_commit_hook.py

@@ -1,10 +1,9 @@
 #!/usr/bin/env python
 # vim:fileencoding=utf-8
 # License: GPLv3 Copyright: 2008, Kovid Goyal <kovid at kovidgoyal.net>
-
+from __future__ import print_function
 
 import importlib
-from __future__ import print_function
 import json
 import re
 import socket