Change SaltStack updates repository and deploy openstack job

The commit changes current salstack update settings to target to the
newly created salt 2017.7.8 repository. Also this introduces a new option
in the "Deploy Openstack" jenkins job to control whether to update
salt packages.

Closes-Bug: PROD-35233
Closes-Bug: PROD-35355
Change-Id: Idb85175eab5a0c423f6b0e15d5ea35b3e156f209
2 files changed