Show the datafile name even with no dives

That's especially useful if starting without a filename and without an
existing default file - this way it's clear that Subsurface still
considers itself synced with the default file.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

main.c

@@ -246,7 +246,7 @@ int main(int argc, char **argv)
 		set_filename(filename, FALSE);
 	}
 	report_dives(imported);
-
+	show_dive_info(NULL);
 	run_ui();
 	exit_ui();
 	return 0;