Fix typo in replace_listener config and refactor (#291)

* Fix typo in replace_listener config and refactor

* Fix version

Author: ines

setup.cfg

@@ -1,5 +1,5 @@
 [metadata]
-version = 1.0.5
+version = 1.0.6
 description = spaCy pipelines for pre-trained BERT and other transformers
 url = https://spacy.io
 author = Explosion

spacy_transformers/layers/_util.py

@@ -13,9 +13,7 @@ def replace_listener_cfg(tok2vec_model_cfg, listener_model_cfg):
         and "TransformerListener" in listener_model_cfg["@architectures"]
     ):
         result["@architectures"] = "spacy-transformers.Tok2VecTransformer.v1"
-        if "pooling" in listener_model_cfg and "pooling" not in result:
-            result["pooling"] = listener_model_cfg["pooling"]
-        if "grad_factor" in listener_model_cfg and "grad_factor" not in result:
-            result["grad_factor"] = listener_model_cfg["pooling"]
-
+        for key in ["pooling", "grad_factor"]:
+            if key in listener_model_cfg and key not in result:
+                result[key] = listener_model_cfg[key]
     return result