Fix build on Debian 9.

diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index 0e6e908b3245c88fb8e9851e4e898a452c8d64bb..5102697935b6565b1d1598079acafab871de05cd 100644 (file)
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -816,7 +816,7 @@ FilmViewer::set_crop_guess (dcpomatic::Rect<float> crop)
 void
 FilmViewer::unset_crop_guess ()
 {
-       _crop_guess = {};
+       _crop_guess = boost::none;
        _video_view->update ();
 }