puppet: Only use those "modern" options when on xenial.
puppet: Only use those "modern" options when on xenial.

On trusty, we of course have an older version -- 1.4.14 -- and it is
not so modern, so this just gives an error.

showell/zulip,timabbott/zulip,tommyip/zulip,rht/zulip,eeshangarg/zulip,shubhamdhama/zulip,eeshangarg/zulip,rishig/zulip,eeshangarg/zulip,rishig/zulip,jackrzhang/zulip,brainwane/zulip,kou/zulip,timabbott/zulip,jackrzhang/zulip,synicalsyntax/zulip,shubhamdhama/zulip,jackrzhang/zulip,dhcrzf/zulip,jackrzhang/zulip,timabbott/zulip,shubhamdhama/zulip,rht/zulip,synicalsyntax/zulip,hackerkid/zulip,synicalsyntax/zulip,timabbott/zulip,brainwane/zulip,showell/zulip,rht/zulip,showell/zulip,hackerkid/zulip,brainwane/zulip,hackerkid/zulip,timabbott/zulip,tommyip/zulip,andersk/zulip,dhcrzf/zulip,synicalsyntax/zulip,zulip/zulip,rht/zulip,andersk/zulip,showell/zulip,shubhamdhama/zulip,kou/zulip,jackrzhang/zulip,jackrzhang/zulip,dhcrzf/zulip,punchagan/zulip,tommyip/zulip,rht/zulip,tommyip/zulip,timabbott/zulip,eeshangarg/zulip,tommyip/zulip,zulip/zulip,tommyip/zulip,shubhamdhama/zulip,dhcrzf/zulip,rht/zulip,punchagan/zulip,andersk/zulip,hackerkid/zulip,kou/zulip,shubhamdhama/zulip,hackerkid/zulip,rht/zulip,eeshangarg/zulip,kou/zulip,hackerkid/zulip,punchagan/zulip,hackerkid/zulip,brainwane/zulip,shubhamdhama/zulip,synicalsyntax/zulip,brainwane/zulip,synicalsyntax/zulip,zulip/zulip,tommyip/zulip,punchagan/zulip,jackrzhang/zulip,rishig/zulip,kou/zulip,andersk/zulip,punchagan/zulip,zulip/zulip,rishig/zulip,dhcrzf/zulip,punchagan/zulip,brainwane/zulip,dhcrzf/zulip,zulip/zulip,brainwane/zulip,kou/zulip,dhcrzf/zulip,rishig/zulip,zulip/zulip,rishig/zulip,zulip/zulip,showell/zulip,synicalsyntax/zulip,punchagan/zulip,andersk/zulip,kou/zulip,showell/zulip,showell/zulip,timabbott/zulip,rishig/zulip,eeshangarg/zulip,andersk/zulip,eeshangarg/zulip,andersk/zulip