The only place where we could return wide characters with -httpd
was the raw $INBOX_DIR/description text, which is now converted
to octets.
All daemon (HTTP/NNTP/IMAP) sockets are opened in binary mode,
so length() and bytes::length() are equivalent on reads. For
socket writes, any non-octet data would warn about wide characters
and we are strict in warnings with test_httpd.
All gzipped buffers are also octets, as is PublicInbox::Eml->body,
and anything from PerlIO objects ("git cat-file --batch" output,
filesystems), so bytes::length was unnecessary in all those places.