DOC: track status for stale comment in gbq docs

#5179 introduced the following warning

As of 10/10/13, there is a bug in Google’s API preventing result sets from being 
larger than 100,000 rows. A patch is scheduled for the week of 10/14/13.

@jacobschaer, is this still valid?

[jacobschaer]

The patch was released, though a new bug has similar limitations. I'll double check the status of this.

As long as that comment has an expected expiry date, keeping this open.

[jreback]

@jacobschaer shall we remove this comment from the docs?