git: openjdk/jtharness: (build) build.number incremented to b19

[Dmitry Bessonov]

Changeset: a701e785
Author:    Dmitry Bessonov <dmitry.bessonov at oracle.com>
Date:      2021-06-10 13:05:35 +0000
URL:       https://git.openjdk.java.net/jtharness/commit/a701e78565bd5779e56b3549ba21769b6b02dda0

(build) build.number incremented to b19

! build/build.properties