bpo-30109: Fix reindent.py for non-ASCII files. (#5637)

It now processes files as binary streams.

This also fixes "make reindent".
diff --git a/Lib/email/utils.py b/Lib/email/utils.py
index a74db42..5b22521 100644
--- a/Lib/email/utils.py
+++ b/Lib/email/utils.py
@@ -213,7 +213,7 @@
 def parseaddr(addr):
     """
     Parse addr into its constituent realname and email address parts.
-    
+
     Return a tuple of realname and email address, unless the parse fails, in
     which case return a 2-tuple of ('', '').
     """