_get_custom_css results in sass.CompileError when custom_scss path is not found by finders

[kbakk]

I have set Bulma settings to

BULMA_SETTINGS = {
    "custom_scss": [
        "cant/find/this.scss"
    ]
}

I expect to see ValueError: Unable to locate the SCSS file .... However I get an unhelpful sass.CompileError instead:

sass.CompileError: Error: File to import not found or unreadable: [].

It looks like this package has an helpful error that should be show, however

django-simple-bulma/django_simple_bulma/finders.py

Line 170 in 3e3eac8

if absolute_path is None:

when this step is run, the value is an empty list [], so the comparison to None is evaluated as false.

Suggestion: Change expression to if not absolute_path (I can submit a PR with that if desired).