Fix cider-popup-buffer-display with multiple frames.

[nealsid]

If you set cider-popup-buffer-display to nil, but are using multiple
frames, the call to display-buffer doesn't currently set the required
extra parameter in the alist to stop Emacs from switching to that
frame. This small PR fixes that.

• The commits are consistent with our contribution guidelines
• You've added tests (if possible) to cover your change(s)
• All tests are passing (make test)
• The new code is not generating bytecode or M-x checkdoc warnings
• You've updated the changelog (if adding/changing user-visible functionality)
• You've updated the readme (if adding/changing user-visible functionality)
• You've updated the refcard (if you made changes to the commands listed there)

[bbatsov]

Guess you should add a comment explaining the need for this here.

[nealsid]

Done

[bbatsov]

Looks good to me. Two small things, though:

• drop the . from the commit's title
• mention this as a bugfix in the changelog

[nealsid]

Thanks! Addressed your comments. Let me know if anything else is needed.

[bbatsov]

I still don't see a changelog entry for the bugfix.

[nealsid]

Woops, I misunderstood what you meant by Changelog, I thought you meant something else. I'll push another commit later on today. Thanks!

[bbatsov]

ping :-)

[nealsid]

Done! Really sorry for the delay, this was a crazy week at work. I merged master and rebased my commits. Let me know if anything doesn't look right.