This avoids a warning from msgfmt:
$ msgfmt -v -o mercurial/locale/zh_TW/LC_MESSAGES/hg.mo i18n/zh_TW.po -c
i18n/zh_TW.po:7: warning: header field 'Language' still has the
initial default value
When generating documentation, indentation must match for getting the same
view for translated messages. Often an output is generated anyway, but it
can look different. When a syntactically wrong indentation change is done,
runrst will fail (this is detected by test-gendoc.t).
Fix the simple places. When translation knowledge is necessary, the entry is
marked as fuzzy (and therefore skipped when generating translations). A
translator can fix it later.