Prevent errors incase collectd is disabled on first install
Prevent errors incase collectd is disabled on first install

A user can concivably attempt to install collectd with
'collectd_controller: false' and thus will encounter the same error
as noted in https://review.openstack.org/#/c/333510/

Change-Id: I1643c8a9b5c80c284d0eb3835634fb4b958650c3

jkilpatr/browbeat,jkilpatr/browbeat