py3: use pycompat.sysargv in scmposix.systemrcpath()
sys.argv returns unicodes on Python 3. We have pycompat.sysargv which returns
bytes encoded using os.fsencode(). After this patch scmposix.systemrcpath()
returns bytes in Python 3 world. This change is also a part of making
`hg version` run in Python 3.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true