Description of problem:
Since the update to dnf 4.2.1 and libdnf 0.28.0, the Spacewalk plugin is no longer compatible with DNF, and now DNF crashes whenever it tries to run anything, since the plugin fails to load because the ConfigParser implementation is incomplete compared to the old iniparse implementation.

Version-Release number of selected component (if applicable):
0.28.0-1.fc29

How reproducible:
Always

Steps to Reproduce:
1. Install dnf-plugin-spacewalk
2. Run "dnf status"

Actual results:

Crashes with traceback:
$ dnf status
Traceback (most recent call last):
  File "/usr/bin/dnf", line 58, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python3.7/site-packages/dnf/cli/main.py", line 192, in user_main
    errcode = main(args)
  File "/usr/lib/python3.7/site-packages/dnf/cli/main.py", line 64, in main
    return _main(base, args, cli_class, option_parser_class)
  File "/usr/lib/python3.7/site-packages/dnf/cli/main.py", line 95, in _main
    cli.configure(list(map(ucd, args)), option_parser())
  File "/usr/lib/python3.7/site-packages/dnf/cli/cli.py", line 902, in configure
    self.base.init_plugins(opts.disableplugin, opts.enableplugin, self)
  File "/usr/lib/python3.7/site-packages/dnf/base.py", line 316, in init_plugins
    self._plugins._run_init(self, cli)
  File "/usr/lib/python3.7/site-packages/dnf/plugin.py", line 149, in _run_init
    plugin = p_cls(base, cli)
  File "/usr/lib/python3.7/site-packages/dnf-plugins/spacewalk.py", line 68, in __init__
    options = self.parser.items("main")
  File "/usr/lib64/python3.7/site-packages/libdnf/conf.py", line 1826, in <lambda>
    __getattr__ = lambda self, name: _swig_getattr(self, ConfigParser, name)
  File "/usr/lib64/python3.7/site-packages/libdnf/conf.py", line 80, in _swig_getattr
    raise AttributeError("'%s' object has no attribute '%s'" % (class_type.__name__, name))
AttributeError: 'ConfigParser' object has no attribute 'items'


Expected results:
DNF loads properly.

Additional info: