Gracefully handle expect, unsupported activities

bookwyrm/activitypub/base_activity.py

@@ -52,10 +52,14 @@ def naive_parse(activity_objects, activity_json, serializer=None):
         if activity_json.get("publicKeyPem"):
             # ugh
             activity_json["type"] = "PublicKey"
+
+        activity_type = activity_json.get("type")
         try:
-            activity_type = activity_json["type"]
             serializer = activity_objects[activity_type]
         except KeyError as e:
+            # we know this exists and that we can't handle it
+            if activity_type in ["Question"]:
+                return None
             raise ActivitySerializerError(e)
 
     return serializer(activity_objects=activity_objects, **activity_json)