fix merging default config and type based config

preprocessor/preprocessor/preprocess.py

@@ -170,9 +170,9 @@ def preprocess_file(config: dict, file_path: os.PathLike, use_dir: os.PathLike=N
 
         # get a concrete configuration for the type, filled with the defaults
         default_config = dict(config['preprocessing'].get('defaults', {}))
-        preprocess_config = dict(config['preprocessing']['types'].get(product_type, {}))
-        default_config.update(preprocess_config)
-
+        type_based_config = dict(config['preprocessing']['types'].get(product_type, {}))
+        default_config.update(type_based_config)
+        preprocess_config = default_config
         logger.debug('Using preprocessing config %s' % pformat(preprocess_config))
 
         if not os.path.isdir('unpack'):