The spacewalk-export --list-entities fails with error "'str' object has no attribute 'format'"

Issue

• The spacewalk-export command fails with below error,

# spacewalk-export --list-entities
INFO: Currently-supported entities include:
Traceback (most recent call last):
  File "/usr/bin/spacewalk-export", line 279, in ?
    listSupported()
  File "/usr/bin/spacewalk-export", line 117, in listSupported
    logging.info('{0:20} : {1}'.format(s, SUPPORTED_ENTITIES[s]))
AttributeError: 'str' object has no attribute 'format'