Fix problem with scale being a multidimensional array.

[jurevreca12]

In case scale is a multidimensional array (e.g. 1 x num_channels) scale[0] does not return a scalar. Instead
scale.item(0) should be used.

I had this problem on the model added bellow. It has channel-wise scaling factors. The problem was
that the match function returned an array, which then lead to errors (truth value of an array is ambiguous).

The change should not affect the rest of the code, nor does it change behavior.
Since the change is so trivial, I didn't bother adding a test. However, if this is deemed desired, I
can also add a test.

Type of change:

• Bug fix (non-breaking change that fixes an issue)
• Documentation update
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• A new research paper code implementation
• Other (Specify)

Tests

None

Checklist

• I have read the guidelines for contributing.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have installed and run pre-commit on the files
• I have added tests that prove my fix is effective or that my feature works.

cnn_model.zip

[jmitrevs]

This looks good. Let's just double-check the pytests before merging.