[multi-asic] Fix for sonic-cfggen exception during platform string re…

…ad (#8229)

Fix for sonic-cfggen exception during platform string read during fresh install and start of sonic in multi asic, /var/run/redisX/ is created after database docker is started.

src/sonic-config-engine/sonic-cfggen

@@ -302,10 +302,6 @@ def main():
                                 'localhost': {'namespace_id': namespace_id}
                              }
                           })
-    # Load the database config for the namespace from global database json
-    if args.namespace is not None:
-        SonicDBConfig.load_sonic_global_db_config(namespace=args.namespace)
-
     if hwsku is not None:
         hardware_data = {'DEVICE_METADATA': {'localhost': {
             'hwsku': hwsku
@@ -354,6 +350,7 @@ def main():
         if args.namespace is None:
             configdb = ConfigDBPipeConnector(use_unix_socket_path=use_unix_sock, **db_kwargs)
         else:
+            SonicDBConfig.load_sonic_global_db_config(namespace=args.namespace)
             configdb = ConfigDBPipeConnector(use_unix_socket_path=use_unix_sock, namespace=args.namespace, **db_kwargs)
 
         configdb.connect()
@@ -414,6 +411,7 @@ def main():
         if args.namespace is None:
             configdb = ConfigDBPipeConnector(use_unix_socket_path=True, **db_kwargs)
         else:
+            SonicDBConfig.load_sonic_global_db_config(namespace=args.namespace)
             configdb = ConfigDBPipeConnector(use_unix_socket_path=True, namespace=args.namespace, **db_kwargs)
 
         configdb.connect(False)