fix: Helm chart model needs default

Author: alhendrickson

deployment/kubernetes/charts/medcat-service-helm/values.yaml

@@ -32,7 +32,7 @@ env:
   # DEID_REDACT: true
 
 # Enable downloading of public models using wget on startup. Model will be downloaded to /models/<name> and used for APP_MEDCAT_MODEL_PACK
-# model:
+model: {}
   # Public URL to download a model pack from
   # downloadUrl: "http://localhost:9000/models/my-model.zip"
   # Name of the model pack to save to. Will be stored at /models/<name>