- Only clear the OSG ‘pose as standalone’ flag when we really show
a dialog, as opposed to when we /might/ show.
Tested:
- Qt build using launcher
- No Qt build
- Qt build but launcher not requested
- add a button to the main dialog, explaining how to adjust the
fg-root path via the GUI
- tweak the GUI flow to support explicitly changing the path even
when the default path is acceptable.