doc: mknews: support Email::MIME <1.930

Email::MIME::header_str is not available until 1.930, so the
rest of our code uses Email::MIME::header for compatibility
with distros, since CentOS 7.x only has 1.926.

diff --git a/Documentation/mknews.perl b/Documentation/mknews.perl
index e78c1cb87c57062e074abe37c0d0becce69c36dc..5ede36964287ce2cfb673f54f54ccf36cfcd298a 100755 (executable)
--- a/Documentation/mknews.perl
+++ b/Documentation/mknews.perl
@@ -80,7 +80,7 @@ sub release2mime {
 
 sub mime2txt {
        my ($out, $mime) = @_;
-       my $title = $mime->header_str('Subject');
+       my $title = $mime->header('Subject');
        $title =~ s/^\s*\[\w+\]\s*//g; # [ANNOUNCE] or [ANN]
        my $dtime = msg_datestamp($mime->header_obj);
        $title .= ' - ' . PublicInbox::View::fmt_ts($dtime) . ' UTC';