mid: capitalize "ID" in "Message-ID"

Prefer the "ID" capitalization since it seems to to be the
preferred capitalization in RFC 5322.

In theory, this allows the interpreter to deduplicate the string
internally (I haven't checked if it does).

Unfortunately, there's too many instances of "Message-Id" in the
tests to be worth changing at this point.

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/PublicInbox/MID.pm b/lib/PublicInbox/MID.pm
index dddde092..685306db 100644
--- a/lib/PublicInbox/MID.pm
+++ b/lib/PublicInbox/MID.pm
@@ -72,7 +72,7 @@ sub extract_mids {
 
 sub mids ($) {
         my ($hdr) = @_;
-        my @mids = $hdr->header_raw('Message-Id');
+        my @mids = $hdr->header_raw('Message-ID');
         uniq_mids(extract_mids(@mids));
 }
 
@@ -81,7 +81,7 @@ sub mids ($) {
 # import and index without relying on HTTP endpoints
 sub mids_for_index ($) {
         my ($hdr) = @_;
-        my @mids = $hdr->header_raw('Message-Id');
+        my @mids = $hdr->header_raw('Message-ID');
         my @alts = $hdr->header_raw('X-Alt-Message-ID');
         uniq_mids(extract_mids(@mids, @alts));
 }