[niepce] niepce-main: no need to upcast

[Hubert Figuière <hub src gnome org>]

commit 5cd4fd876affd970f4d5dc84ae433c7d200ce76d
Author: Hubert Figuière <hub figuiere net>
Date:   Fri Jun 5 22:34:08 2020 -0400

    niepce-main: no need to upcast

 niepce-main/src/niepce/ui/thumb_strip_view.rs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/niepce-main/src/niepce/ui/thumb_strip_view.rs b/niepce-main/src/niepce/ui/thumb_strip_view.rs
index c9428bd..81da7e4 100644
--- a/niepce-main/src/niepce/ui/thumb_strip_view.rs
+++ b/niepce-main/src/niepce/ui/thumb_strip_view.rs
@@ -152,9 +152,7 @@ impl ThumbStripViewPriv {
 
         self.store.replace(model.clone());
         self.setup_model();
-        self.get_instance()
-            .upcast::<gtk::IconView>()
-            .set_model(model.as_ref());
+        self.get_instance().set_model(model.as_ref());
     }
 
     fn setup_model(&self) {
@@ -172,7 +170,7 @@ impl ThumbStripViewPriv {
             };
             self.item_count.set(count);
 
-            let view = self.get_instance().upcast::<gtk::IconView>();
+            let view = self.get_instance();
             // update item count
             self.item_count.update(&view);