puppet: Ensure zulip user owns key /etc/zulip files.
puppet: Ensure zulip user owns key /etc/zulip files.

The main purpose of this change is to make it guaranteed that
`manage.py register_server --rotate-key` can edit the
/etc/zulip/zulip-secrets.conf configuration via crudini.

But it also adds value by ensuring zulip-secrets.conf is not readable
by other users.

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