fix for config saving issue

[asylves1]

Description

Issue:

• Extracting an inputs from a document in the model config then changing an input value and saving does not save the new value

Testing:

• upload a document and model to a workflow
• create a model config and add the model & document
• extract the inputs from the document
• make changes to a few of the inputs and save
• check that the inputs have been updated in the new config

Resolves #(issue)