BUG: force list type for tuples from chunked sql table reads #11522
Closes #11522.

@grahamjeffries Looks good! thanks

This is actually in code that is deprecated, and will be removed in the future. But as it is only a small change, ok to let this in for the case it will not yet be removed in the next version.
 Sure thing. Yeah, I wasn't quite sure what the protocol was for testing cases which fail with an exception. I'll update the PR
 @grahamjeffries OK! Just a last question, can you add a note in the whatsnew file (doc/source/whatsnew/v0.18.0.txt) in the bug fixes section, and then also squash the commits? (http://pandas.pydata.org/pandas-docs/stable/contributing.html#combining-commits)
 Noted and squashed.
 Thanks a lot!
