tests/readlink.py

test-convert-git: drop a git warning that doesn't occur on Windows

I do see this on Linux with 1.7.7.6, but not on Windows with 1.9.5.msysgit.0.
Adding a (?) didn't work to conditionally ignore the line; I'm not sure if the
(glob) interferes with that.

#!/usr/bin/env python

import errno, os, sys

for f in sys.argv[1:]:
    try:
        print f, '->', os.readlink(f)
    except OSError as err:
        if err.errno != errno.EINVAL:
            raise
        print f, 'not a symlink'

sys.exit(0)