Avoid attribute error on user_config

Closes #129 (closed)

arkindex_worker/worker/base.py

@@ -196,7 +196,7 @@ class BaseWorker(object):
         )
 
         # Retrieve initial configuration from API
-        self.config = worker_version["configuration"]["configuration"]
+        self.config = worker_version["configuration"].get("configuration")
         if "user_configuration" in worker_version["configuration"]:
             # Add default values (if set) to user_configuration
             for key, value in worker_version["configuration"][
@@ -210,8 +210,10 @@ class BaseWorker(object):
         self.secrets = {name: self.load_secret(name) for name in required_secrets}
 
         # Load worker run configuration when available
-        worker_configuration = worker_run.get("configuration", {})
-        self.user_configuration = worker_configuration.get("configuration")
+        worker_configuration = worker_run.get("configuration")
+        self.user_configuration = (
+            worker_configuration.get("configuration") if worker_configuration else None
+        )
         if self.user_configuration:
             logger.info("Loaded user configuration from WorkerRun")
             # if debug mode is set to true activate debug mode in logger