Minor bugfix: Fix format string parameters for ClientError

Author: woodlee

src/confluent_kafka/avro/cached_schema_registry_client.py

@@ -461,7 +461,7 @@ def update_compatibility(self, level, subject=None):
         if code >= 200 and code <= 299:
             return result['compatibility']
         else:
-            raise ClientError("Unable to update level: %s. Error code: %d" % (str(level)), code)
+            raise ClientError("Unable to update level: %s. Error code: %d" % (str(level), code))
 
     def get_compatibility(self, subject=None):
         """