configure_hotkeys: Pass the dialog as a parent to SequenceDialog()

Without passing in a parent, this can result in focus being stolen from
the dialog in certain cases.

Example:

On Windows, if the logging window is left open, the logging Window will
potentially get focus over the hotkey dialog itself, since it brings all
open windows for the application into view. By specifying a parent, we
only bring windows for the parent into view (of which there are none,
aside from the hotkey dialog).