blackbox: do not translate the log messages
User 'timeless' in irc mentioned that having the blackbox be
translated would result in logs that:
- may be mixed language, if multiple users use the same repo
- are not google searchable (since searching for english gives more
results)
- might not be readable by an admin if the employee is using hg in
his native language
And therefore we should log everything in english.
Testing that hghave does not crash when checking features
$ "$TESTDIR/hghave" --test-features 2>/dev/null