py3: write out hgextindex as bytes in setup.py
I hit this trying to build the py2exe target using python3, just to see what
would happen. After commenting out `py2exe.Distribution` in setup.py and
pointing to a local copy of py2exe that supports python3[1], it complained that
`out` was bytes, not str.
[1] https://github.com/albertosottile/py2exe/releases/tag/v0.9.3.0
#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories
# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"
# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
#import sys; sys.path.insert(0, "/path/to/python/lib")
# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()
from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi
application = hgweb(config)
wsgicgi.launch(application)