virt-who errors out with TypeError: string indices must be integers, not str

Issue

When running virt-who the following error occurs:

# virt-who -od

...
2018-03-16 10:01:27,412 [rhsm.connection DEBUG] MainProcess(20298):MainThread @connection.py:_request:490 - Making request: POST /subscription/hypervisors/1979710?reporter_id=ktordeur-sat58.kenny.lan&cloaked=False&env=Library
2018-03-16 10:01:29,014 [rhsm.connection INFO] MainProcess(20298):MainThread @connection.py:_request:525 - Response: status=202, requestUuid=5d8d494e-1284-4459-b825-a7c750b681d7, request="POST /subscription/hypervisors/1979710?reporter_id=ktordeur-sat58.kenny.lan&cloaked=False&env=Library"
2018-03-16 10:01:29,015 [rhsm.connection WARNING] MainProcess(20298):MainThread @connection.py:_request:529 - Clock skew detected, please check your system time
2018-03-16 10:01:29,015 [virtwho.main DEBUG] MainProcess(20298):MainThread @executor.py:send_report:116 - Report for config "vcenter" sent
2018-03-16 10:01:44,022 [virtwho.main DEBUG] MainProcess(20298):MainThread @subscriptionmanager.py:_connect:124 - Authenticating with certificate: /etc/pki/consumer/cert.pem
2018-03-16 10:01:44,023 [rhsm.connection INFO] MainProcess(20298):MainThread @connection.py:__init__:758 - Connection built: host=subscription.rhsm.redhat.com port=443 handler=/subscription auth=identity_cert ca_dir=/etc/rhsm/ca/ insecure=0
2018-03-16 10:01:44,024 [rhsm.connection DEBUG] MainProcess(20298):MainThread @connection.py:_request:490 - Making request: GET /subscription/status/
2018-03-16 10:01:45,378 [rhsm.connection INFO] MainProcess(20298):MainThread @connection.py:_request:525 - Response: status=200, requestUuid=8edaa19d-7702-4d94-9ec8-57a342874558, request="GET /subscription/status/"
2018-03-16 10:01:45,379 [rhsm.connection WARNING] MainProcess(20298):MainThread @connection.py:_request:529 - Clock skew detected, please check your system time
2018-03-16 10:01:45,379 [virtwho.main DEBUG] MainProcess(20298):MainThread @subscriptionmanager.py:check_report_state:226 - Checking status of job hypervisor_update_d44181c8-efa4-462c-9683-801a1548ebfc
2018-03-16 10:01:45,381 [rhsm.connection DEBUG] MainProcess(20298):MainThread @connection.py:_request:490 - Making request: GET /subscription/jobs/hypervisor_update_d44181c8-efa4-462c-9683-801a1548ebfc?result_data=True
2018-03-16 10:01:46,762 [rhsm.connection INFO] MainProcess(20298):MainThread @connection.py:_request:525 - Response: status=200, requestUuid=311e2620-a93b-45a4-8951-1b5c382ce9d3, request="GET /subscription/jobs/hypervisor_update_d44181c8-efa4-462c-9683-801a1548ebfc?result_data=True"
2018-03-16 10:01:46,763 [rhsm.connection WARNING] MainProcess(20298):MainThread @connection.py:_request:529 - Clock skew detected, please check your system time
string indices must be integers, not str
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/virtwho/__main__.py", line 11, in main
    res = virtwho.main.main()
  File "/usr/lib/python2.6/site-packages/virtwho/main.py", line 183, in main
    return _main(executor)
  File "/usr/lib/python2.6/site-packages/virtwho/main.py", line 192, in _main
    result = executor.run()
  File "/usr/lib/python2.6/site-packages/virtwho/executor.py", line 301, in run
    report_state = self.check_report_state(self.reports_in_progress.items()[0][1])
  File "/usr/lib/python2.6/site-packages/virtwho/executor.py", line 81, in check_report_state
    manager.check_report_state(report)
  File "/usr/lib/python2.6/site-packages/virtwho/manager/subscriptionmanager/subscriptionmanager.py", line 253, in check_report_state
    guests = [x['guestId'] for x in updated['guestIds']]
TypeError: string indices must be integers, not str
2018-03-16 10:01:46,764 [virtwho.main ERROR] MainProcess(20298):MainThread @__main__.py:main:19 - Fatal error:
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/virtwho/__main__.py", line 11, in main
    res = virtwho.main.main()
  File "/usr/lib/python2.6/site-packages/virtwho/main.py", line 183, in main
    return _main(executor)
  File "/usr/lib/python2.6/site-packages/virtwho/main.py", line 192, in _main
    result = executor.run()
  File "/usr/lib/python2.6/site-packages/virtwho/executor.py", line 301, in run
    report_state = self.check_report_state(self.reports_in_progress.items()[0][1])
  File "/usr/lib/python2.6/site-packages/virtwho/executor.py", line 81, in check_report_state
    manager.check_report_state(report)
  File "/usr/lib/python2.6/site-packages/virtwho/manager/subscriptionmanager/subscriptionmanager.py", line 253, in check_report_state
    guests = [x['guestId'] for x in updated['guestIds']]
TypeError: string indices must be integers, not str
2018-03-16 10:01:46,765 [virtwho.main DEBUG] MainProcess(20298):MainThread @executor.py:terminate:337 - virt-who is shutting down