old_contents: #!/usr/bin/env python
  import os
  import sys
  from six import raise_from
  msg = ("Couldn't import Django. Are you sure it's installed and "
         "available on your PYTHONPATH environment variable? Did you "
         "forget to activate a virtual environment?")
  
  if __name__ == '__main__':
      os.environ.setdefault("DJANGO_SETTINGS_MODULE",
                            "django_contacts.settings")
      try:
          from django.core.management import execute_from_command_line
      except ImportError as exc:
          raise_from(ImportError(msg), exc)
      execute_from_command_line(sys.argv)
new_contents: #!/usr/bin/env python
  import os
  import sys
  from six import raise_from
  msg = ("Couldn't import Django. Are you sure it's installed and "
         "available on your PYTHONPATH environment variable? Did you "
         "forget to activate a virtual environment?")
  
  if __name__ == '__main__':
      os.environ.setdefault("DJANGO_SETTINGS_MODULE",
                            "django_contacts.settings")
      try:
          from django.core.management import execute_from_command_line
      except ImportError as exc:
          raise_from(ImportError(msg), exc)
      execute_from_command_line(sys.argv)
  
subject: fix flake8 error