hg: openjfx/8u-dev/rt: Follow-on for RT-36330 to print the supported gradle version on failure

[hang . vo]

Changeset: 6c7047fd93f0
Author:    kcr
Date:      2014-03-21 17:15 -0700
URL:       http://hg.openjdk.java.net/openjfx/8u-dev/rt/rev/6c7047fd93f0

Follow-on for RT-36330 to print the supported  gradle version on failure

! build.gradle