[niepce] rust: remove unnecessary unsafe

[Hubert Figuière <hub src gnome org>]

commit 6e9ed0fa9069de74a57bf389a31fbece731a7fe9
Author: Hubert Figuière <hub figuiere net>
Date:   Fri Feb 22 07:59:56 2019 -0500

    rust: remove unnecessary unsafe

 src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/lib.rs b/src/lib.rs
index 2f2580b..32bc2f0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -51,7 +51,7 @@ use std::sync::{Once, ONCE_INIT};
 pub extern "C" fn niepce_init() {
     static START: Once = ONCE_INIT;
 
-    START.call_once(|| unsafe {
+    START.call_once(|| {
         gtk::init().unwrap();
         rexiv2::initialize().expect("Unable to initialize rexiv2");
     });