hg: jdk/sandbox: 8208647: switch jtreg to 4.2b13

[chris.hegarty at oracle.com]

Changeset: a306c84e40fa
Author:    iignatyev
Date:      2018-08-01 23:06 -0700
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/a306c84e40fa

8208647: switch jtreg to 4.2b13
Reviewed-by: kvn, dholmes, ihse

! make/conf/jib-profiles.js
! test/failure_handler/src/share/classes/jdk/test/failurehandler/jtreg/GatherDiagnosticInfoObserver.java