Fix typo: pipe.quotes => pipes.quote

hey @stoned - here's a small change that fixes a problem I ran into while testing your fix-3521 branch:

    Traceback (most recent call last):
      File "/home/local/AD/username/ansible/bin/ansible-playbook", line 235, in <module>
        sys.exit(main(sys.argv[1:]))
      File "/home/local/AD/username/ansible/bin/ansible-playbook", line 181, in main
        pb.run()
      File "/home/local/AD/username/ansible/lib/ansible/playbook/__init__.py", line 217, in run
        play = Play(self, play_ds, play_basedir)
      File "/home/local/AD/username/ansible/lib/ansible/playbook/play.py", line 72, in __init__
        ds = self._load_roles(self.roles, ds)
      File "/home/local/AD/username/ansible/lib/ansible/playbook/play.py", line 191, in _load_roles
        nt = dict(include=pipe.quotes(handler), vars=has_dict)
    NameError: global name 'pipe' is not defined