Fix reference leak in constructor
Fix reference leak in constructor

MadBomber/concurrent-ruby,MadBomber/concurrent-ruby,hobodave/concurrent-ruby,lucasallan/concurrent-ruby,hobodave/concurrent-ruby,hobodave/concurrent-ruby,MadBomber/concurrent-ruby,lucasallan/concurrent-ruby,hobodave/concurrent-ruby,lucasallan/concurrent-ruby,MadBomber/concurrent-ruby,lucasallan/concurrent-ruby,lucasallan/concurrent-ruby