(SERVER-150) flush jruby instances

I understand your point, but I think I'm on the opposite side of the fence on this one.  Curiosity got the best of me, so ... https://github.com/KevinCorcoran/puppet-server/commit/8e17a155bbfd2bc9e8f8fe84a995b84090ad99ed

I'm okay with the code as you have it now, but I think the patch above is an improvement.