Fix broken Swift debugger

[chrisballinger]

Debugging in Swift is basically impossible now and nothing seems to work to restore our ability to properly debug.

For example:

(lldb) po otrRow
error: Error in auto-import:
failed to get module 'ChatSecureCore' from AST context:
(lldb) po otrRow
error: Swift expressions require OS X 10.10 / iOS 8 SDKs or later.

[chrisballinger]

Maybe it's a problem in the project file. I'm pretty sure it used to work back around these commits:

commit 4480aa6e335cdc69f0477c1932399d4c17ec7216
Author: Chris Ballinger <chrisballinger@gmail.com>
Date:   Mon Oct 10 16:26:37 2016 -0700

    Bump XMPPFramework

commit f6edf76f043549ef39d31df8bf90650def685628
Author: Chris Ballinger <chrisballinger@gmail.com>
Date:   Mon Oct 10 16:13:06 2016 -0700

    Fix remaining warnings regarding duplicate definitions

commit 89d4e484f3ae682437c02379a4a5438ec4289f53
Author: Chris Ballinger <chrisballinger@gmail.com>
Date:   Mon Oct 10 16:06:44 2016 -0700

    Support duplicate deviceId for keyData in OMEMOModule

commit e0606b2d083d36e04527367228aa2ff6f7690a9f
Author: Chris Ballinger <chrisballinger@gmail.com>
Date:   Fri Oct 7 17:14:02 2016 -0700

    Fix most warnings