Description of problem:
Playbook with empty vars_files section.

Version-Release number of selected component:
ansible-0.8-1.fc17

Additional info:
libreport version: 2.0.18
abrt_version:   2.0.18
cmdline:        /usr/bin/python /usr/bin/ansible-playbook -i hosts-tests tests.yml
kernel:         3.6.10-2.fc17.x86_64

backtrace:
:utils.py:387:template:AttributeError: 'NoneType' object has no attribute 'decode'
:
:Traceback (most recent call last):
:  File "/usr/bin/ansible-playbook", line 164, in <module>
:    sys.exit(main(sys.argv[1:]))
:  File "/usr/bin/ansible-playbook", line 135, in main
:    pb.run()
:  File "/usr/lib/python2.7/site-packages/ansible/playbook/__init__.py", line 170, in run
:    play = Play(self, play_ds, play_basedir)
:  File "/usr/lib/python2.7/site-packages/ansible/playbook/play.py", line 81, in __init__
:    self._update_vars_files_for_host(None)
:  File "/usr/lib/python2.7/site-packages/ansible/playbook/play.py", line 303, in _update_vars_files_for_host
:    filename2 = utils.template(self.basedir, filename, self.vars)
:  File "/usr/lib/python2.7/site-packages/ansible/utils.py", line 387, in template
:    text = text.decode('utf-8')
:AttributeError: 'NoneType' object has no attribute 'decode'
:
:Local variables in innermost frame:
:text: None
:vars: {}
:basedir: ''
:expand_lists: False
:prev_text: ''