commit 3f93f147dba84c41f836430bf0e09481f2e4498c
Author: Rabi Mishra <ramishra@redhat.com>
Date:   Wed Sep 30 17:52:59 2020 +0530

    Handle None config for networkConfig
    
    This would allow us to set NetworkConfig to OS::Heat::None
    
    Change-Id: I695ac3a0565932334be31a5c7f162c926422bf6e

diff --git a/tripleo_common/utils/config.py b/tripleo_common/utils/config.py
index 229b6f7..1d7730c 100644
--- a/tripleo_common/utils/config.py
+++ b/tripleo_common/utils/config.py
@@ -229,6 +229,9 @@ class Config(object):
             config_path = os.path.join(config_dir, role, "NetworkConfig")
             # check if it's actual config or heat config_id
             # this will be dropped once we stop using SoftwareConfig
+            if config is None:
+                continue
+
             if isinstance(config, dict):
                 str_config = json.dumps(config)
             else: