ci: update centos6 platform to use the "vault" since el6 is EOL
ci: update centos6 platform to use the "vault" since el6 is EOL

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp