Move list config into "config" and don't config lists when absent

mailman_sync.py

@@ -3,12 +3,14 @@
 """
 Update Mailman 2 lists via a json API of the form:
 {
-  "LIST": {
-    "real_name": "REAL_NAME",
-    "moderator": ["ADDRESS", ...],
-    "subject_prefix": "PREFIX",
-    "reply_to_address": "REPLY_TO_ADDRESS",
-    "members": ["ADDRESS", ...]
+  LIST: {
+    "config"?: {
+      "real_name": REAL_NAME,
+      "moderator": [ADDRESS, ...],
+      "subject_prefix": PREFIX,
+      "reply_to_address": REPLY_TO_ADDRESS,
+    }
+    "members": [ADDRESS, ...]
   },
   ...
 }
@@ -161,14 +163,11 @@ def main(
             else:
                 list_manager.newlist(urlhost, emailhost, admin)
 
+        if "config" in props:
             print(f"Configuring/syncing {list_name}...")
-        list_manager.config_list(
-            emailhost,
-            props["real_name"],
-            props["moderator"],
-            props["subject_prefix"],
-            props["reply_to_address"],
-        )
+            list_manager.config_list(emailhost, **props["config"])
+        else:
+            print("Not configuring {list_name}, as it has no config section")
         list_manager.sync_members(props["members"])