fix: catch AttributeError in config check for non-dict WEBPACK_LOADER

[saschabuehrle]

Bug

#427 — The webpack_cfg_check system check crashes with AttributeError: 'list' object has no attribute 'values' when WEBPACK_LOADER is set to a non-dict value (e.g. a list or None).

Fix

Added AttributeError to the existing except TypeError clause in webpack_cfg_check(). When WEBPACK_LOADER is a list, string, None, or any other non-dict type, calling .values() raises AttributeError instead of TypeError. By catching both, the function now correctly returns the BAD_CONFIG_ERROR diagnostic instead of crashing.

Testing

Verified that:

• Non-dict configs (list, string, None) now return a BAD_CONFIG_ERROR check result instead of crashing
• Valid dict configs continue to work as before
• The existing TypeError path (dicts with non-dict values) still triggers correctly

Happy to address any feedback.

Greetings, saschabuehrle