Potential error when calling quickview without model

[Nazeef-Noorie]

pyfhd/src/pyfhd/pyfhd.py

Line 627 in 3f4691a

quickview(

1. Argument "cal" passed, which is not initialized when the model file path is set to None (or when calibration checkpoint is false).
2. "model_uv[pol_i]" referenced within the quickview function, which would throw an error when model_uv is None (when not providing a model)