nntp: remove unused header_append method

It was unused since 1bf653ad139bf7bb3d853ab0b5eae3eaa1b13a95
("nntp+www: drop List-* and Archived-At headers")

1 files changed, 0 insertions, 9 deletions

diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index 18822d3b..f7d99913 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -409,15 +409,6 @@ sub cmd_quit ($) {
         undef;
 }
 
-sub header_append ($$$) {
-        my ($hdr, $k, $v) = @_;
-        my @v = $hdr->header_raw($k);
-        foreach (@v) {
-                return if $v eq $_;
-        }
-        $hdr->header_set($k, @v, $v);
-}
-
 sub xref_by_tc ($$$) {
         my ($xref, $pi_cfg, $smsg) = @_;
         my $by_addr = $pi_cfg->{-by_addr};