[Fix] Collection of minor Bugfixes (#417)

User feedback from on-prem installation

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#417

bridge/contracts.py

@@ -254,7 +254,14 @@ class Classifier(Plugin):
     def parse_config(cls, data: dict | None = None) -> EnviPyModel | None:
         if cls.Config is None:
             return None
-        return cls.Config(**(data or {}))
+
+        # remove empty strings a.k.a unset params to not overwrite defaults
+        cpy = {}
+        if data is not None:
+            for k, v in data.items():
+                if v != "":
+                    cpy[k] = v
+        return cls.Config(**cpy)
 
     @classmethod
     def create(cls, data: dict | None = None):