py3: resolve Unicode issues around `hg serve` on Windows...
py3: resolve Unicode issues around `hg serve` on Windows
Presumably we're going to want to use CreateProcessW(), and possibly get rid of
pycompat.getcwd() here (which maps to the DeprecationWarning causing
os.getcwdb()) to use os.getcwd() directly. But this was a minimal change to
get rid of some stacktraces in test-run-tests.t.
