Midstream fix to work around mongo packaging issues

This isn't seen upstream but is a problem in instack due to the version
of mongo being used. This change explicitly highlights which mongo
configuration file to use.

Change-Id: Ide682d666f7122c5eecc4007498096410dc6b228

puppet/hieradata/controller.yaml

@@ -12,6 +12,7 @@ rabbitmq::package_source: undef
 rabbitmq::repos_ensure: false
 
 mongodb::server::replset: tripleo
+mongodb::server::config: '/etc/mongod.conf'
 
 redis::port: 6379
 redis::sentinel::master_name: "%{hiera('bootstrap_nodeid')}"