misc/lv: Update to 4.51.20200728

• Add support of compressed file by zstd(1)

The maintainer has applied the patch from the submitter to upstream. And then
update this port to the upstream snapshot.

PR: 248267
Submitted by: Yasuhiro KIMURA <yasu@utahime.org> (initial revision)
Reviewed by: meta (myself)
Approved by: IWAMOTO Kouichi <sue@iwmt.org> (maintainer, upstream developer)