crash if user chooses not to move

[mr-fixit]

On some machine/macOS versions, our app would crash with

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSApp with wrong _running count'

after the user clicked the 'do not move' button.

We avoided the crash by calling PFMoveToApplicationsFolderIfNecessary inside of application *DID* FinishLaunching instead of application *WILL* FinishLaunching.