removed unused and erroring cmp import

lib/ansible/executor/play_iterator.py

@@ -24,7 +24,6 @@ import fnmatch
 from ansible.compat.six import iteritems
 from ansible import constants as C
 from ansible.errors import AnsibleError
-from ansible.module_utils.six import cmp
 from ansible.playbook.block import Block
 from ansible.playbook.task import Task
 from ansible.playbook.role_include import IncludeRole