[BUG] Configuration check prevents using --edit-config

[Markus00000]

Describe the bug
When config.yaml contains unrecognized options, a ValueError prevents fixing them using webchanges --edit-config.

To Reproduce
Add unrecognized options to config.yaml manually with an editor, then try to remove them using webchanges --edit-config.

Expected behavior
Fixing a broken configuration should always be possible with --edit-config. If the configuration check is run after saving config.yaml, it can still warn about unrecognized options that have not been fixed. Another possibility would be to show a prompt with a warning message when invoking --edit-config with an invalid configuration.

Version info
2021-08-03 08:55:26,577 cli DEBUG: webchanges: 3.8.1 Copyright 2020- Mike Borsetti
2021-08-03 08:55:26,577 cli DEBUG: Python: ('default', 'Jun 30 2021 10:22:16')
2021-08-03 08:55:26,580 cli DEBUG: System: Linux-5.13.7-arch1-1-x86_64-with-glibc2.33

[mborsetti]

I just released v3.8.2, which fixes this logic error. Thanks so much for reporting it; very much appreciated! 🎉