Upgrade gerrit from 2.9.3 to 2.9.4
Upgrade gerrit from 2.9.3 to 2.9.4

socialwifi/docker-gerrit,openfrontier/docker-gerrit,piete/docker-gerrit,ravihuang/zuul,ravihuang/gerrit_cn,garethjevans/docker-gerrit,ravihuang/gerrit_cn