_ascii_split(): Don't lstrip continuation lines.  Closes SF bug #601392.
diff --git a/Lib/email/Header.py b/Lib/email/Header.py
index 2457279..70e0bac 100644
--- a/Lib/email/Header.py
+++ b/Lib/email/Header.py
@@ -250,7 +250,7 @@
                 maxlinelen = self._firstlinelen
                 firstline = 0
             else:
-                line = line.lstrip()
+                #line = line.lstrip()
                 maxlinelen = self._maxlinelen
             # Short lines can remain unchanged
             if len(line.replace('\t', SPACE8)) <= maxlinelen: