supress invalid cookie header messages in scheduler

These seem to not cause problems, but do gum up the logs quite a bit.

```
 20251210-17:46:17: [WARN]: Invalid cookie header: "set-cookie: __cf_bm=H8JubQ4HgxXziaVfS3UIYs923ZbTD4WzB.3Z0KA2CzM-1765388776.238819-1.0.1.1-JC.IQ84Ev6TDH5ib
```