commit: don't use hard-coded `.hg/last-message.txt` path in error message
Whoever wrote D8463 just used a hard-coded path to
`.hg/last-message.text` instead of using the relative path that was
already available in the `msgfn` variable (and used just a few lines
up in related message). Let's fix that.
Differential Revision: https://phab.mercurial-scm.org/D12585
[build-system]
requires = ["setuptools", "wheel"]
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true