Construct correct yum repo URL with facts

$releasever results in "6Server" on RHEL 6.4.
Revert "Construct correct yum repo URL with facts"

This reverts commit 52ad15e0fb905d9be0884bf909c37058db481585.
Don't set empty arrays for subscribers/handlers

 - empty array for check-handler avoids sensu-server to use default
   handler
 - I don't want to set default handler on all puppet checks