Insights-client fails to register the system when using --group option in the command.

Issue

• insights-client fails to register host when using --group option in the command like below:-

  # insights-client --register --group="tag"
  Fatal error
  Traceback (most recent call last):
   File "/var/lib/insights/newest.egg/insights/client/phase/v1.py", line 32, in _f
     func(client, config)
   File "/var/lib/insights/newest.egg/insights/client/phase/v1.py", line 198, in post_update
     reg = client.register()
   File "/var/lib/insights/newest.egg/insights/client/__init__.py", line 72, in _init_connection
     return func(self, *args, **kwargs)
   File "/var/lib/insights/newest.egg/insights/client/__init__.py", line 406, in register
     return client.handle_registration(self.config, self.connection)
   File "/var/lib/insights/newest.egg/insights/client/client.py", line 189, in handle_registration
     return _legacy_handle_registration(config, pconn)
   File "/var/lib/insights/newest.egg/insights/client/client.py", line 151, in _legacy_handle_registration
     message, hostname, group, display_name = register(config, pconn)
   File "/var/lib/insights/newest.egg/insights/client/client.py", line 109, in register
      return pconn.register()
   File "/var/lib/insights/newest.egg/insights/client/connection.py", line 786, in register
     self.do_group()
   File "/var/lib/insights/newest.egg/insights/client/connection.py", line 624, in do_group
     self.group_systems(group_id, systems)
   File "/var/lib/insights/newest.egg/insights/client/connection.py", line 599, in group_systems
     api_group_id = get_group.json()['id']
  TypeError: list indices must be integers, not str
  Fatal error
  Traceback (most recent call last):
   File "/etc/insights-client/rpm.egg/insights/client/phase/v1.py", line 32, in _f
     func(client, config)
   File "/etc/insights-client/rpm.egg/insights/client/phase/v1.py", line 195, in post_update
     reg = client.register()
   File "/etc/insights-client/rpm.egg/insights/client/__init__.py", line 74, in _init_connection
     return func(self, *args, **kwargs)
   File "/etc/insights-client/rpm.egg/insights/client/__init__.py", line 408, in register
     return client.handle_registration(self.config, self.connection)
   File "/etc/insights-client/rpm.egg/insights/client/client.py", line 189, in handle_registration
     return _legacy_handle_registration(config, pconn)
   File "/etc/insights-client/rpm.egg/insights/client/client.py", line 151, in _legacy_handle_registration
     message, hostname, group, display_name = register(config, pconn)
   File "/etc/insights-client/rpm.egg/insights/client/client.py", line 109, in register
     return pconn.register()
   File "/etc/insights-client/rpm.egg/insights/client/connection.py", line 778, in register
     self.do_group()
   File "/etc/insights-client/rpm.egg/insights/client/connection.py", line 613, in do_group
     self.group_systems(group_id, systems)
   File "/etc/insights-client/rpm.egg/insights/client/connection.py", line 580, in group_systems
     api_group_id = get_group.json()['id']
  TypeError: list indices must be integers, not str