git: a5913a473bb0..a509d68f27b9 - vendor/libarchive - vendor branch updated

[Martin Matuska]

The branch vendor/libarchive has been updated by mm:

URL: https://cgit.FreeBSD.org/src/log/?id=a5913a473bb0..a509d68f27b9

a509d68f27b9 Update vendor/libarchive to 3.7.3