fixup! media/create: enforce limit on number of pending uploads

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>

synapse/storage/databases/main/media_repository.py

@@ -483,10 +483,10 @@ async def count_pending_media(self, user_id: UserID) -> Tuple[int, int]:
 
         def get_pending_media_txn(txn: LoggingTransaction) -> Tuple[int, int]:
             sql = """
-            SELECT COUNT(*), MIN(created_at)
+            SELECT COUNT(*), MIN(created_ts)
             FROM local_media_repository
             WHERE user_id = ?
-                AND created_at > ?
+                AND created_ts > ?
                 AND media_length IS NULL
             """
             txn.execute(
@@ -501,7 +501,7 @@ def get_pending_media_txn(txn: LoggingTransaction) -> Tuple[int, int]:
                 return 0, 0
             return row[0], (row[1] + self.unused_expiration_time if row[1] else 0)
 
-        return await self.db_pool.runInteraction("get_url_cache", get_pending_media_txn)
+        return await self.db_pool.runInteraction("get_pending_media", get_pending_media_txn)
 
     async def get_url_cache(self, url: str, ts: int) -> Optional[UrlCache]:
         """Get the media_id and ts for a cached URL as of the given timestamp