Remove max_requests_per_instance since hiera-eyaml is fixed

Prior to this commit, we mitigated issues with hiera-eyaml causing
a memory leak by setting max_requets_per_instance to 0

After this commit, we go back to the default for
max_requests_per_instance because the hiera-eyaml memory leak
has been resolved for months if you use the newest version

Author: npwalker

hieradata/common.yaml

@@ -1,5 +1,2 @@
 ---
 message: "This node is using common data"
-
-#Puppet Server Tuning
-puppet_enterprise::master::puppetserver::jruby_max_requests_per_instance: 0