Resolve "release v1.4.0"

Closes #317 (closed)

mlair/model_modules/fully_connected_networks.py

@@ -120,8 +120,8 @@ class FCN(AbstractModelClass):
             raise AttributeError(f"Given optimizer {optimizer} is not supported in this model class.")
 
     def _set_regularizer(self, regularizer, **kwargs):
-        if regularizer is None:
-            return regularizer
+        if regularizer is None or (isinstance(regularizer, str) and regularizer.lower() == "none"):
+            return None
         try:
             reg_name = regularizer.lower()
             reg = self._regularizer.get(reg_name)