[Openstack-i18n] Horizon upstream_translation_update Jenkins job

Hi Daisy, Perhaps RC1 may be shipped this week and the master branch will be opened to Juno development. Even after the master branch is opened to Juno, Transifex resources are still targeted to Icehouse translations. We need to disable upstream_translation_update for Horizon temporarily. Otherwise Transifex resources will be synced with Juno code. Could you coordinate it with the infra team? At now Horizon is the only project whose translation work is being done synced with the release cycle and we tend to encounter the first thing :-( Thanks, Akihiro