include collectd only on centos and fedora

It does not exist in RHEL, so don't include it.

Change-Id: I4eddc0c6e8a8a8618d57e307a7750b2b80d23bfd
Bug-Url:  https://bugzilla.redhat.com/980365
Signed-off-by: Mike Burns <mburns@redhat.com>