hg: jdk10/sandbox: 8186095: upgrade to jtreg 4.2 b08

[chris.hegarty at oracle.com]

Changeset: 45e0cf8cf984
Author:    iignatyev
Date:      2017-08-20 20:36 -0700
URL:       http://hg.openjdk.java.net/jdk10/sandbox/rev/45e0cf8cf984

8186095: upgrade to jtreg 4.2 b08
Reviewed-by: rriggs, mchung, dholmes, iklam

! common/conf/jib-profiles.js