incorrect permissions on archive index file

[Rohanc]

The index file for list archives is created with the wrong
file permissions. I'm referring to:

mailman/archives/private/ --listname-- / index.html

All my lists have index.html set to "rw-rw-rw-" which
seems too permissive.

I think this can be corrected by modifiying the
Archiver.InitVars method inside the file:

   mailman/Mailman/Archiver/Archiver.py .

I just added:
   os.umask(omask)
before the line that reads:
   fp = open(indexfile, 'w')

I run Mailman 2.1.3.

[http://sourceforge.net/tracker/index.php?func=detail&aid=835012&group_id=103&atid=100103]