NameError when there is no hmac

Author: thaelathy

.gitignore

@@ -3,4 +3,5 @@
 *.DS_Store
 *.pypirc
 releaseguide.md
-
+venv/
+.idea/

Adyen/client.py

@@ -308,9 +308,8 @@ def call_hpp(self, message, action, hmac_key="", **kwargs):
 
         # hmac provided in function has highest priority. fallback to self then
         # root module and ensure that it is set.
-        if hmac_key:
-            hmac = hmac_key
-        elif self.hmac:
+        hmac = hmac_key
+        if self.hmac:
             hmac = self.hmac
         elif not hmac:
             errorstring = """Please set an hmac with your Adyen.Adyen class instance.