[niepce] rust+test: fix build from gtk-rs update

[Hubert Figuière <hub src gnome org>]

commit fb8e037a16ca38f6c2c0b8e7d994ccf09455268f
Author: Hubert Figuière <hub figuiere net>
Date:   Sat Jul 4 23:35:45 2020 -0400

    rust+test: fix build from gtk-rs update

 niepce-main/examples/widget-test.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/niepce-main/examples/widget-test.rs b/niepce-main/examples/widget-test.rs
index 8b3698d..2968080 100644
--- a/niepce-main/examples/widget-test.rs
+++ b/niepce-main/examples/widget-test.rs
@@ -40,7 +40,7 @@ fn init() -> Result<(), Error> {
 
     // Create Resource it will live as long the value lives.
     let gbytes = Bytes::from_static(res_bytes.as_ref());
-    let resource = Resource::new_from_data(&gbytes)?;
+    let resource = Resource::from_data(&gbytes)?;
 
     // Register the resource so it won't be dropped and will continue to live in
     // memory.