bug#52787: Debbugs doesn't recognize Chinese "Re:" prefix in email messages

[Eli Zaretskii]

Package: debbugs.gnu.org

It looks like debbugs doesn't recognize the Chinese spelling of "Re:"
in the email messages it receives.  See bug#52655 for an example.
There, the message at https://debbugs.gnu.org/cgi/bugreport.cgi?bug=52655#23,
as shown in the Web UI of debbugs, had this Subject:

   Subject: 回复: bug#52655: 29.0.50 pgtk bug on X Window.

But the respective message disseminated to the bug-gnu-emacs mailing
list, which I received, has this Subject instead:

   Subject: bug#52655: 回复: bug#52655: 29.0.50 pgtk bug on X Window.

That is, "bug#52655: " was prepended to the Subject, probably because
the "回复: " variant of "Re:" was not recognized?  Or maybe this is a
problem with the MUA/MTA used by debbugs?

The net result is that grouping email messages by Subject is broken on
my end, at least in Rmail, because, even though Rmail does know about
the "回复: " thing, the Subject I receive doesn't begin with it, so it
is not filtered out for the purposes of comparing Subjects.

Can this be fixed, please?