sshpeer: make client print (likely) server errors on stderr (BC)
so `hg clone -q` or `hg pull -q` don't print `abort: no suitable
response from remote hg!` with no indication of what went wrong.
There are other errors still silenced by -q (like failing to push due
to a server hook), but the current change covers a good fraction of
the problem (all errors setting up the ssh connection, no such remote
repository, no access to the repository).
Differential Revision: https://phab.mercurial-scm.org/D8584
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true