[perf] check duplicat accept respond

app/boxes.py

@@ -166,9 +166,15 @@ async def process_incoming(
         ).unique().scalar_one_or_none()
 
         if "Accept" == ap_object["type"]:
+            try:
                 inbox_object = build_object(ap_object)
                 db_session.add(inbox_object)
                 await db_session.flush()
+            except IntegrityError:
+                logger.warning("Duplicate accept respond?")
+                await db_session.rollback()
+                return True
+
             await db_session.refresh(inbox_object)
 
             following = models.Following(