UPDATE_MASTER hardcoded to True if we use UPDATE_FUEL_MIRROR

[Artem Hrechanychenko]

Need to change default behavior of setting env variable UPDATE_MASTER because we have acceptance job which used FORCE_DISABLE_UPDATES=True and in fuel-qa we have https://github.com/openstack/fuel-qa/blob/stable/mitaka/fuelweb_test/tests/base_test_case.py#L183

https://github.com/fuel-infra/jenkins-jobs/blob/master/common/9.x/builders/wrapped_system_tests.sh#L118-L119

to
if [[ -n "${UPDATE_FUEL_MIRROR}" ]] ; then
    UPDATE_MASTER=${UPDATE_MASTER:-true}

[Artem Hrechanychenko (agrechanichenko)]

https://review.fuel-infra.org/#/c/27168/

[Dmitry Belyaninov (dbelyaninov)]

updated job
https://product-ci.infra.mirantis.net/view/9.x_acceptance/job/9.x.acceptance.ubuntu.install_mu_no_ha_failover/configure

Properties Content:
UPDATE_MASTER=False
FORCE_DISABLE_UPDATES=True

shell script:
...
# UPDATE_MASTER=true in case when we have set some repos
# otherwise there will be no reason to start updating without any repos to update from

if [[ -n "${UPDATE_FUEL_MIRROR}" ]] ; then
    UPDATE_MASTER=${UPDATE_MASTER:-true}
fi
...