[gnome-font-viewer] font-view: fix crash when changing scale factor

[Cosimo Cecchi <cosimoc src gnome org>]

commit 7a45968fb5b67d060a84ae52e9509db48a358385
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Mon Oct 30 15:26:36 2017 -0700

    font-view: fix crash when changing scale factor
    
    We were not passing the right parameter to the signal callback.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=789511

 src/font-view.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/font-view.c b/src/font-view.c
index ad87935..919cae8 100644
--- a/src/font-view.c
+++ b/src/font-view.c
@@ -748,8 +748,8 @@ font_view_ensure_model (FontViewApplication *self)
     g_signal_connect (self->model, "config-changed",
                       G_CALLBACK (font_model_config_changed_cb), self);
 
-    g_signal_connect (self->main_window, "notify::scale-factor",
-                      G_CALLBACK (font_view_update_scale_factor), self);
+    g_signal_connect_swapped (self->main_window, "notify::scale-factor",
+                              G_CALLBACK (font_view_update_scale_factor), self);
     font_view_update_scale_factor (self);
 }