Fix server playback backfill session filter

backfill_playback_times.py

@@ -31,8 +31,8 @@ def run_backfill(session_id=None, progress=None):
         while True:
             params = {"select": "action_id,session_id,start_frame,end_frame", "start_time_seconds": "is.null",
                       "order": "action_id", "limit": "1000", "offset": str(offset)}
-            if args.session_id:
-                params["session_id"] = f"eq.{args.session_id}"
+            if session_id:
+                params["session_id"] = f"eq.{session_id}"
             response = client.get(f"{url}/actions", params=params)
             response.raise_for_status()
             page = response.json()