contrib/showstack.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.

# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)

import sys, signal, traceback

def sigshow(*args):
    sys.stderr.write("\n")
    traceback.print_stack(args[1], limit=10, file=sys.stderr)
    sys.stderr.write("----\n")

def extsetup(ui):
    signal.signal(signal.SIGQUIT, sigshow)
    try:
        signal.signal(signal.SIGINFO, sigshow)
    except AttributeError:
        pass