Fix VNish get_config for list-based autotune presets response is a list

[MinersNederland]

Summary

This fixes a VNish parsing issue where get_config() assumes autotune_presets() returns a dict and calls .get("presets", []).

Some VNish miners return a list instead, which caused:

• AttributeError: 'list' object has no attribute 'get'
• wrapped as APIError: Failed to call config ... while getting data

What changed

• Updated VNish config handling to support both response shapes:
  • dict response: use response.get("presets", [])
  • list response: use the list directly
  • unexpected type: fallback to empty list

Why

This prevents get_data() from failing on miners that return list-based preset payloads, while preserving existing behavior for dict-based responses.

Validation

• Reproduced failure on an S19j Pro running VNish v1.2.6 before the change.
• Re-ran data collection after the fix; config now loads successfully and get_data() completes, reutning a valid pyasic.data.MinerData object containing all expected data

Compatibility

Backward compatible: existing dict-based VNish responses still behave the same.

Human AI Review

This fix was created with Github Copilot and has been human reviewed (albeit by an amateur ;P )