bpo-29919: Remove unused imports found by pyflakes (#137)

Make also minor PEP8 coding style fixes on modified imports.
diff --git a/Lib/gettext.py b/Lib/gettext.py
index aa1d555..08d051b 100644
--- a/Lib/gettext.py
+++ b/Lib/gettext.py
@@ -46,7 +46,12 @@
 #   find this format documented anywhere.
 
 
-import locale, copy, io, os, re, struct, sys
+import copy
+import locale
+import os
+import re
+import struct
+import sys
 from errno import ENOENT