githttpbackend: remove unused $BIN variable

It hasn't been used in many years since commit
c1630b7dc4ef (githttpbackend: match Content-Type of git-http-backend(1), 2016-07-03)

diff --git a/lib/PublicInbox/GitHTTPBackend.pm b/lib/PublicInbox/GitHTTPBackend.pm
index 72b8e6c3403f4db6edaebf2c089396f144c73a4e..1eb51f2704e1f2f06414d7f8db78b9c08ef743fc 100644 (file)
--- a/lib/PublicInbox/GitHTTPBackend.pm
+++ b/lib/PublicInbox/GitHTTPBackend.pm
@@ -27,7 +27,6 @@ my @binary = ('objects/[a-f0-9]{2}/[a-f0-9]{38,62}',
        'objects/pack/pack-[a-f0-9]{40,64}\.(?:pack|idx)');
 
 our $ANY = join('|', @binary, @text, 'git-upload-pack');
-my $BIN = join('|', @binary);
 my $TEXT = join('|', @text);
 
 sub serve {