I submitted an update of my game to the App Store about a week ago, after having given up on fixing this prompt. Of course, despite getting approved the first time, my update was rejected for the rogue location services prompt.
I did some more digging and FINALLY determined the cause: It seems to be the Touch plugin within Construct 2. Once I deleted it from my game, I no longer saw the location services prompt after exporting to iOS. Of course, this also meant that my game was totally unplayable (no touch controls).
I thought it was insane that the Touch plugin would be causing this, so I made an empty project with nothing but a Text object (to make sure something was showing on the screen) and the Touch plugin. Sure enough, when I uploaded the project to Adobe PhoneGap and opened the app on my iPhone, it popped up the location services prompt.
Can anyone explain what's happening here? Is this some sort of bug? I'd really like to kill this prompt and get my update approved, but removing the Touch plugin from my project isn't really an option.